2008 INFINITI QX56 Fuel

CHG
POWER GENERATION VOLTAGE VARIABLE CONTROL SYSTEM
CHG-9
< FUNCTION DIAGNOSIS >
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POWER GENERATION VOLTAG
E VARIABLE CONTROL SYSTEM
System DiagramINFOID:0000000001696181
System DescriptionINFOID:0000000001696182
Power generation variable voltage control system has been adopted. By varying the voltage to the generator,
engine load due to power generation of the generator is reduced and fuel consumption is decreased.
NOTE:
When any malfunction is detected in the power generat ion variable voltage control system, power generation
is performed according to the characterist ic of the IC regulator in the generator.
Component DescriptionINFOID:0000000001696183
ALMIA0057GB
Component part Description
Battery current sensor The battery current sensor is installed on the battery cable at the
negative terminal. The battery current sensor detects the charg-
ing/discharging current of the battery and sends a voltage signal
to the ECM according to the current value detected.
ECM The battery current sensor detects the charging/discharging cur-
rent of the battery. The ECM judges the battery condition based on
this signal.
The ECM judges whether to request more output via the power
generation voltage variable control according to the battery condi-
tion.
When performing the power generation voltage variable control,
the ECM calculates the target power generation voltage according
to the battery condition and sends the calculated value as the pow-
er generation command value to the IPDM E/R.
IPDM E/R The IPDM E/R converts the received power generation command
value into a pulse width modulated (PWM) command signal and
sends it to the IC regulator.
Generator (IC regulator) The IC regulator controls the power generation voltage by the tar-
get power generation voltage based on the received PWM com-
mand signal.
When there is no PWM command signal, the generator performs
the normal power generation according to the characteristic of the
IC regulator.
Revision: March 2010
2008 QX56

EC-1
ENGINE
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SECTION EC
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CONTENTS
ENGINE CONTROL SYSTEM
VK56DE
BASIC INSPECTION ....... .............................
8
DIAGNOSIS AND REPAIR WORKFLOW ..... .....8
Trouble Diagnosis Introduction ........................... ......8
INSPECTION AND ADJUSTMENT ....................13
Basic Inspection .................................................. ....13
Idle Speed and Ignition Timing Check ....................17
Procedure After Replacing ECM .............................17
VIN Registration ......................................................17
Accelerator Pedal Released Position Learning .......18
Throttle Valve Closed Position Learning .................18
Idle Air Volume Learning .........................................18
FUNCTION DIAGNOSIS ..............................21
ENGINE CONTROL SYSTEM ........................ ....21
System Diagram .................................................. ....21
Engine Control Component Parts Location .............22
MULTIPORT FUEL INJECTION SYSTEM ..... ....28
System Description ............................................. ....28
ELECTRIC IGNITION SYSTEM ..................... ....31
System Description ............................................. ....31
AIR CONDITIONING CUT CONTROL ...............32
Input/Output Signal Chart .................................... ....32
System Description .................................................32
AUTOMATIC SPEED CONTROL DEVICE
(ASCD) ...............................................................
33
System Description ............................................. ....33
Component Description ...........................................34
CAN COMMUNICATION ....................................35
System Description ............................................. ....35
COOLING FAN CONTROL ................................36
Description ..............................................................36
EVAPORATIVE EMISSION SYSTEM ...............37
Description ........................................................... ....37
INTAKE VALVE TIMING CONTROL ................40
Description ...............................................................40
ON BOARD DIAGNOSTIC (OBD) SYSTEM ....41
Introduction ..............................................................41
Two Trip Detection Logic .........................................41
Emission-related Diagnostic Information .................42
Malfunction Indicator Lamp (MIL) ............................55
OBD System Operation Chart .................................58
CONSULT-III Function (ENGINE) ...........................63
Generic Scan Tool (GST) Function .........................72
COMPONENT DIAGNOSIS .........................75
TROUBLE DIAGNOSIS - SPECIFICATION
VALUE ...............................................................
75
Description ........................................................... ....75
Testing Condition .....................................................75
Inspection Procedure ...............................................75
Diagnosis Procedure ...............................................76
POWER SUPPLY AND GROUND CIRCUIT ....83
Diagnosis Procedure ...............................................83
Ground Inspection ...................................................86
U1000, U1001 CAN COMM CIRCUIT ...............87
Description ...............................................................87
On Board Diagnosis Logic .......................................87
DTC Confirmation Procedure ..................................87
Diagnosis Procedure ...............................................87
U1010 CONTROL UNIT (CAN) .........................88
Description ...............................................................88
On Board Diagnosis Logic .......................................88
DTC Confirmation Procedure ..................................88
Diagnosis Procedure ...............................................88
P0011, P0021 IVT CONTROL ...........................90
On Board Diagnosis Logic .......................................90
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EC-3
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Diagnosis Procedure ...........................................
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160
Component Inspection ..........................................162
P0138, P0158 HO2S2 ......................................164
Component Description ....................................... ..164
On Board Diagnosis Logic ....................................164
DTC Confirmation Procedure ................................164
Overall Function Check .........................................165
Diagnosis Procedure .............................................166
Component Inspection ..........................................169
P0139, P0159 HO2S2 ......................................171
Component Description ....................................... ..171
On Board Diagnosis Logic ....................................171
DTC Confirmation Procedure ................................171
Overall Function Check .........................................172
Diagnosis Procedure .............................................172
Component Inspection ..........................................174
P0171, P0174 FUEL INJECTION SYSTEM
FUNCTION .......................................................
176
On Board Diagnosis Logic .................................. ..176
DTC Confirmation Procedure ................................176
Diagnosis Procedure .............................................179
P0172, P0175 FUEL INJECTION SYSTEM
FUNCTION .......................................................
182
On Board Diagnosis Logic .................................. ..182
DTC Confirmation Procedure ................................182
Diagnosis Procedure .............................................185
P0181 FTT SENSOR ........................................188
Component Description ....................................... ..188
On Board Diagnosis Logic ....................................188
DTC Confirmation Procedure ................................188
Diagnosis Procedure .............................................189
Component Inspection ..........................................190
P0182, P0183 FTT SENSOR ...........................191
Component Description ....................................... ..191
On Board Diagnosis Logic ....................................191
DTC Confirmation Procedure ................................191
Diagnosis Procedure .............................................191
Component Inspection ..........................................193
P0222, P0223 APP SENSOR ...........................194
Component Description .........................................194
On Board Diagnosis Logic ....................................194
DTC Confirmation Procedure ................................194
Diagnosis Procedure .............................................194
Component Inspection ..........................................197
P0300, P0301, P0302, P0303, P0304, P0305,
P0306, P0307, P0308 MISFIRE .......................
198
On Board Diagnosis Logic .................................. ..198
DTC Confirmation Procedure ................................198
Diagnosis Procedure .............................................199
P0327, P0328, P0332, P0333 KS ....................204
Component Description ....................................... ..204
On Board Diagnosis Logic ....................................204
DTC Confirmation Procedure .............................. ..204
Diagnosis Procedure .............................................204
Component Inspection ...........................................206
P0335 CKP SENSOR (POS) ...........................207
Component Description .........................................207
On Board Diagnosis Logic .....................................207
DTC Confirmation Procedure ................................207
Diagnosis Procedure .............................................208
Component Inspection ...........................................209
P0340 CMP SENSOR (PHASE) .....................211
Component Description .........................................211
On Board Diagnosis Logic .....................................211
DTC Confirmation Procedure ................................211
Diagnosis Procedure .............................................212
Component Inspection ...........................................213
P0420, P0430 THREE WAY CATALYST
FUNCTION ......................................................
215
On Board Diagnosis Logic ................................... ..215
DTC Confirmation Procedure ................................215
Overall Function Check .........................................216
Diagnosis Procedure .............................................216
P0441 EVAP CONTROL SYSTEM .................219
System Description ................................................219
On Board Diagnosis Logic .....................................219
DTC Confirmation Procedure ................................219
Overall Function Check .........................................220
Diagnosis Procedure .............................................220
P0442 EVAP CONTROL SYSTEM .................224
On Board Diagnosis Logic .....................................224
DTC Confirmation Procedure ................................224
Diagnosis Procedure .............................................225
Component Inspection ...........................................230
P0443 EVAP CANISTER PURGE VOLUME
CONTROL SOLENOID VALVE ......................
231
Description .............................................................231
On Board Diagnosis Logic .....................................231
DTC Confirmation Procedure ................................231
Diagnosis Procedure .............................................232
Component Inspection ...........................................234
P0444, P0445 EVAP CANISTER PURGE
VOLUME CONTROL SOLENOID VALVE ......
236
Description .............................................................236
On Board Diagnosis Logic .....................................236
DTC Confirmation Procedure ................................237
Diagnosis Procedure .............................................237
Component Inspection ...........................................238
P0447 EVAP CANISTER VENT CONTROL
VALVE .............................................................
239
Component Description .........................................239
On Board Diagnosis Logic .....................................239
DTC Confirmation Procedure ................................239
Diagnosis Procedure .............................................239
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EC-4
Component Inspection ...........................................241
P0448 EVAP CANISTER VENT CONTROL
VALVE .............................................................
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Component Description ....................................... ..243
On Board Diagnosis Logic .....................................243
DTC Confirmation Procedure ................................243
Diagnosis Procedure .............................................244
Component Inspection ...........................................245
P0451 EVAP CONTROL SYSTEM PRES-
SURE SENSOR ...............................................
247
Component Description ....................................... ..247
On Board Diagnosis Logic .....................................247
DTC Confirmation Procedure ................................247
Diagnosis Procedure .............................................247
Component Inspection ...........................................248
P0452 EVAP CONTROL SYSTEM PRES-
SURE SENSOR ...............................................
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Component Description ....................................... ..250
On Board Diagnosis Logic .....................................250
DTC Confirmation Procedure ................................250
Diagnosis Procedure .............................................251
Component Inspection ...........................................253
P0453 EVAP CONTROL SYSTEM PRES-
SURE SENSOR ...............................................
254
Component Description ....................................... ..254
On Board Diagnosis Logic .....................................254
DTC Confirmation Procedure ................................254
Diagnosis Procedure .............................................255
Component Inspection ...........................................258
P0455 EVAP CONTROL SYSTEM ..................259
On Board Diagnosis Logic ................................... ..259
DTC Confirmation Procedure ................................259
Diagnosis Procedure .............................................260
Component Inspection ...........................................264
P0456 EVAP CONTROL SYSTEM ..................266
On Board Diagnosis Logic ................................... ..266
DTC Confirmation Procedure ................................267
Overall Function Check .........................................267
Diagnosis Procedure .............................................268
Component Inspection ...........................................272
P0460 FUEL LEVEL SENSOR ........................274
Component Description ....................................... ..274
On Board Diagnosis Logic .....................................274
DTC Confirmation Procedure ................................274
Diagnosis Procedure .............................................274
P0461 FUEL LEVEL SENSOR ........................276
Component Description ....................................... ..276
On Board Diagnosis Logic .....................................276
Overall Function Check .........................................276
Diagnosis Procedure .............................................277
P0462, P0463 FUEL LEVEL SENSOR ...........278
Component Description ....................................... ..278
On Board Diagnosis Logic ................................... .278
DTC Confirmation Procedure ................................278
Diagnosis Procedure .............................................278
P0500 VSS ........................................................280
Description ........................................................... .280
On Board Diagnosis Logic ....................................280
DTC Confirmation Procedure ................................280
Overall Function Check .........................................281
Diagnosis Procedure .............................................281
P0506 ISC SYSTEM .........................................282
Description ........................................................... .282
On Board Diagnosis Logic ....................................282
DTC Confirmation Procedure ................................282
Diagnosis Procedure .............................................282
P0507 ISC SYSTEM .........................................284
Description ........................................................... .284
On Board Diagnosis Logic ....................................284
DTC Confirmation Procedure ................................284
Diagnosis Procedure .............................................284
P0550 PSP SENSOR .......................................286
Component Description ....................................... .286
On Board Diagnosis Logic ....................................286
DTC Confirmation Procedure ................................286
Diagnosis Procedure .............................................286
Component Inspection ..........................................288
P0603 ECM POWER SUPPLY .........................289
Description ........................................................... .289
DTC Logic .............................................................289
Diagnosis Procedure .............................................289
P0605 ECM .......................................................291
Component Description ....................................... .291
On Board Diagnosis Logic ....................................291
DTC Confirmation Procedure ................................291
Diagnosis Procedure .............................................292
P0643 SENSOR POWER SUPPLY ..................293
On Board Diagnosis Logic ....................................293
DTC Confirmation Procedure ................................293
Diagnosis Procedure .............................................293
P0850 PNP SWITCH ........................................296
Component Description ........................................296
On Board Diagnosis Logic ....................................296
DTC Confirmation Procedure ................................296
Overall Function Check .........................................296
Diagnosis Procedure .............................................297
P1140, P1145 IVT CONTROL POSITION
SENSOR ...........................................................
299
Component Description ....................................... .299
On Board Diagnosis Logic ....................................299
DTC Confirmation Procedure ................................299
Diagnosis Procedure .............................................299
Component Inspection ..........................................302
Revision: March 2010 2008 QX56

EC-6
Component Description .........................................359
On Board Diagnosis Logic .....................................359
DTC Confirmation Procedure ................................359
Diagnosis Procedure .............................................360
P2101 ELECTRIC THROTTLE CONTROL
FUNCTION .......................................................
362
Description ........................................................... ..362
On Board Diagnosis Logic .....................................362
DTC Confirmation Procedure ................................362
Diagnosis Procedure .............................................362
Component Inspection ...........................................365
P2118 THROTTLE CONTROL MOTOR ..........366
Component Description ....................................... ..366
On Board Diagnosis Logic .....................................366
DTC Confirmation Procedure ................................366
Diagnosis Procedure .............................................366
Component Inspection ...........................................367
P2119 ELECTRIC THROTTLE CONTROL
ACTUATOR .....................................................
368
Component Description ....................................... ..368
On Board Diagnosis Logic .....................................368
DTC Confirmation Procedure ................................368
Diagnosis Procedure .............................................369
P2122, P2123 APP SENSOR ..........................370
Component Description ....................................... ..370
On Board Diagnosis Logic .....................................370
DTC Confirmation Procedure ................................370
Diagnosis Procedure .............................................371
Component Inspection ...........................................372
P2127, P2128 APP SENSOR ..........................373
Component Description ....................................... ..373
On Board Diagnosis Logic .....................................373
DTC Confirmation Procedure ................................373
Diagnosis Procedure .............................................373
Component Inspection ...........................................376
P2135 TP SENSOR .........................................377
Component Description ....................................... ..377
On Board Diagnosis Logic .....................................377
DTC Confirmation Procedure ................................377
Diagnosis Procedure .............................................377
Component Inspection ...........................................380
P2138 APP SENSOR ......................................381
Component Description ....................................... ..381
On Board Diagnosis Logic .....................................381
DTC Confirmation Procedure ................................381
Diagnosis Procedure .............................................382
Component Inspection ...........................................384
P2A00, P2A03 A/F SENSOR 1 .......................385
Component Description ....................................... ..385
On Board Diagnosis Logic .....................................385
DTC Confirmation Procedure ................................385
Diagnosis Procedure .............................................386
ASCD BRAKE SWITCH ...................................390
Component Description ....................................... .390
Diagnosis Procedure .............................................390
Component Inspection ..........................................393
ASCD INDICATOR ...........................................394
Component Description ....................................... .394
Diagnosis Procedure .............................................394
COOLING FAN .................................................395
Diagnosis Procedure ............................................ .395
Component Inspection ..........................................395
ELECTRICAL LOAD SIGNAL ..........................397
Description ........................................................... .397
Diagnosis Procedure .............................................397
FUEL INJECTOR ..............................................399
Component Description ....................................... .399
Diagnosis Procedure .............................................399
Component Inspection ..........................................401
FUEL PUMP .....................................................402
Description ........................................................... .402
Diagnosis Procedure .............................................402
Component Inspection ..........................................405
ICC BRAKE SWITCH ..................................... ..406
Component Description ....................................... .406
Diagnosis Procedure .............................................406
Component Inspection ..........................................409
IGNITION SIGNAL ............................................411
Component Description ....................................... .411
Diagnosis Procedure .............................................411
Component Inspection ..........................................414
ON BOARD REFUELING VAPOR RECOV-
ERY (ORVR) .....................................................
416
System Description .............................................. .416
Diagnosis Procedure .............................................416
Component Inspection ..........................................418
POSITIVE CRANKCASE VENTILATION .........421
Description ........................................................... .421
Component Inspection ..........................................421
REFRIGERANT PRESSURE SENSOR ...........423
Component Description ....................................... .423
Diagnosis Procedure .............................................423
ECU DIAGNOSIS ......................................426
ECM ................................................................ ..426
CONSULT-lll Reference Value in Data Monitor
Mode .................................................................... .
426
ECM Harness Connector Terminal Layout ...........429
ECM Terminal and Reference Value ....................429
Wiring Diagram - ENGINE CONTROL SYSTEM - .439
Fail-Safe Chart ......................................................459
DTC Inspection Priority Chart ...............................461
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EC-7
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DTC Index ...........................................................
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462
Emission-related Diagnostic Information ...............466
SYMPTOM DIAGNOSIS ..... .......................481
ENGINE CONTROL SYSTEM SYMPTOMS .. ..481
Symptom Matrix Chart ........................................ ..481
NORMAL OPERATING CONDITION ...............485
Fuel Cut Control (at No Load and High Engine
Speed) ................................................................. ..
485
PRECAUTION ............................................486
PRECAUTIONS .............................................. ..486
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" ............................................................. ..
486
Precaution Necessary for Steering Wheel Rota-
tion After Battery Disconnect ............................... ..
486
On Board Diagnosis (OBD) System of Engine and
A/T .........................................................................
487
Precaution .............................................................487
PREPARATION .........................................491
PREPARATION .............................................. ..491
Special Service Tool ........................................... ..491
Commercial Service Tool ......................................492
ON-VEHICLE MAINTENANCE ..................494
FUEL PRESSURE .......................................... ..494
Fuel Pressure Check .............................................494
EVAP LEAK CHECK ......................................496
How to Detect Fuel Vapor Leakage ..................... ..496
ON-VEHICLE REPAIR ...............................498
EVAP CANISTER ............................................498
Component Inspection ......................................... ..498
Removal and Installation .......................................498
INTAKE VALVE TIMING CONTROL ..............500
Intake Valve Timing Control Solenoid Valve (LH) ..500
Intake Valve Timing Cont rol Solenoid Valve (RH) ..500
Intake Valve Timing Control Position Sensor (LH) ..501
Intake Valve Timing Control Position Sensor (RH) ..501
Camshaft Position Sensor (PHASE) .....................501
SERVICE DATA AND SPECIFICATIONS
(SDS) ............... .......................................... .
503
SERVICE DATA AND SPECIFICATIONS
(SDS) ...............................................................
503
Fuel Pressure ...................................................... ..503
Idle Speed and Ignition Timing ..............................503
Calculated Load Value ..........................................503
Mass Air Flow Sensor ............................................503
Intake Air Temperature Sensor .............................503
Engine Coolant Temperature Sensor ....................503
A/F Sensor 1 Heater ..............................................503
Heated Oxygen sensor 2 Heater ...........................504
Crankshaft Position Sensor (POS) ........................504
Camshaft Position Sensor (PHASE) .....................504
Throttle Control Motor ............................................504
Fuel Injector ...........................................................504
Fuel Pump .............................................................504
Revision: March 2010 2008 QX56

EC-8
< BASIC INSPECTION >[VK56DE]
DIAGNOSIS AND REPAIR WORKFLOW
BASIC INSPECTION
DIAGNOSIS AND REPAIR WORKFLOW
Trouble Diagnosis IntroductionINFOID:0000000001351337
INTRODUCTION
The engine has an ECM to control major systems such as fuel con-
trol, ignition control, idle air control system, etc. The ECM accepts
input signals from sensors and instantly drives actuators. It is essen-
tial that both input and output signals are proper and stable. At the
same time, it is important that there are no malfunctions such as vac-
uum leaks, fouled spark plugs, or
other malfunctions with the engine.
It is much more difficult to diagnose an incident that occurs intermit-
tently rather than continuously. Most intermittent incidents are
caused by poor electric connections or improper wiring. In this case,
careful checking of suspected circuits may help prevent the replace-
ment of good parts.
A visual check only may not find the cause of the incidents. A road
test with CONSULT-III (or GST) or a circuit tester connected should
be performed. Follow the Work Flow on "WORK FLOW" .
Before undertaking actual checks, take a few minutes to talk with a
customer who approaches with a driveability complaint. The cus-
tomer can supply good information about such incidents, especially
intermittent ones. Find out what symptoms are present and under
what conditions they occur. A Di agnostic Worksheet like the example
on "Worksheet Sample" should be used.
Start your diagnosis by looking fo r conventional malfunctions first.
This will help troubleshoot driveability malfunctions on an electroni-
cally controlled engine vehicle.
WORK FLOW
MEF036D
SEF233G
SEF234G
Revision: March 2010 2008 QX56

EC-10
< BASIC INSPECTION >[VK56DE]
DIAGNOSIS AND REPAIR WORKFLOW
2.CHECK DTC*1
1. Check DTC*1 .
2. Perform the following procedure if DTC*
1 is displayed.
- Record DTC*
1 and freeze frame data*2 . (Print them out with CONSULT-III or GST.)
- Erase DTC*
1 . (Refer to EC-462, "DTC Index" .)
- Study the relationship between the cause detected by DTC*
1 and the symptom described by the cus-
tomer. (Symptom Matrix Chart is useful. Refer to EC-481, "
Symptom Matrix Chart" .)
3. Check related service bulletins for information.
Is any symptom described and any DTC detected?
Symptom is described, DTC*1 is displayed>>GO TO 3.
Symptom is described, DTC*
1 is not displayed>>GO TO 4.
Symptom is not described, DTC*
1 is displayed>>GO TO 5.
3.CONFIRM THE SYMPTOM
Try to confirm the symptom described by the customer (except MIL ON).
DIAGNOSIS WORK SHEET is useful to verify the incident.
Connect CONSULT-III to the vehicle and check real time diagnosis results.
Verify relation between the symptom and the condition when the symptom is detected.
>> GO TO 5.
4.CONFIRM THE SYMPTOM
Try to confirm the symptom described by the customer.
DIAGNOSIS WORK SHEET is useful to verify the incident.
Connect CONSULT-III to the vehicle and check real time diagnosis results.
Verify relation between the symptom and the condition when the symptom is detected.
>> GO TO 6.
5.PERFORM DTC CONFIRMATION PROCEDURE
Perform DTC Confirmation Procedure for the displayed DTC* , and then make sure that DTC*
1 is detected
again.
If two or more DTCs*
1 are detected, refer to EC-461, "DTC Inspection Priority Chart" and determine trouble
diagnosis order.
NOTE:
• Freeze frame data*
2 is useful if the DTC*1 is not detected.
• Perform Overall Function Check if DTC Confirma tion Procedure is not included on Service Manual. This
simplified check procedure is an effective alternative though DTC*
1 cannot be detected during this check.
If the result of Overall Function Check is NG, it is the same as the detection of DTC*
1 by DTC Confirmation
Procedure.
Is DTC*
1 detected?
Yes >> GO TO 10.
No >> Check according to GI-38, "
Intermittent Incident" .
6.PERFORM BASIC INSPECTION
Perform EC-13, "
Basic Inspection" .
With CONSULT-III>>GO TO 7.
Without CONSULT-III>>GO TO 9.
7.PERFORM SPEC IN DATA MONITOR MODE
With CONSULT-III
Make sure that “MAS A/F SE-B1”, “B/FUEL SCHDL”, and “A/F ALPHA-B1”, “A/F ALPHA-B2” are within the SP
value using CONSULT-III “SPEC” in “DATA MONITOR” mode. Refer to EC-75
.
Revision: March 2010 2008 QX56