EC-100
[VQ35DE]
TROUBLE DIAGNOSIS
Revision: 2006 January2006 M35/M45
TROUBLE DIAGNOSISPFP:00004
Trouble Diagnosis IntroductionNBS004SY
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-II (or GST) or a circuit tester connected should
be performed. Follow the Work Flow on EC-101
.
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 Diagnostic Worksheet like the example
on EC-105
should be used.
Start your diagnosis by looking for conventional malfunctions first.
This will help troubleshoot driveability malfunctions on an electroni-
cally controlled engine vehicle.
MEF036D
SEF233G
SEF234G
EC-144
[VQ35DE]
TROUBLE DIAGNOSIS
Revision: 2006 January2006 M35/M45
*: Leaving cooling fan OFF with CONSULT-II while engine is running may cause the engine to overheat.
DTC & SRT CONFIRMATION MODE
SRT STATUS Mode
For details, refer to EC-60, "SYSTEM READINESS TEST (SRT) CODE" .
SRT WORK SUPPORT Mode
This mode enables a technician to drive a vehicle to set the SRT while monitoring the SRT status.
DTC WORK SUPPORT Mode
*: DTC P1442 and P1456 does not apply to Y50 models but appears in DTC Work Support Mode screens. FA N D U T Y C O N -
TROL*
Ignition switch: ON
Change duty ratio using CON-
SULT-II.Cooling fan speed changes.
Harness and connectors
Cooling fan motor
Cooling fan relay
Cooling fan control module
IPDM E/R
ALTERNATOR
DUTY
Engine: Idle
Change duty ratio using CON-
SULT-II.Battery voltage changes.
Harness and connectors
IPDM E/R
Alternator TEST ITEM CONDITION JUDGEMENT CHECK ITEM (REMEDY)
Test mode Test item Corresponding DTC No. Reference page
EVAPORATIVE SYSTEMEVP SML LEAK P0442/P1442*P0442EC-403
P0455EC-458
EVP V/S LEAK P0456/P1456* P0456EC-466
PURG VOL CN/V P1444 P0443EC-412
PURG FLOW P0441 P0441EC-398
A/F SEN1A/F SEN1 (B1) P1278/P1279 P0133EC-274A/F SEN1 (B1) P1276 P0130EC-246
A/F SEN1 (B2) P1288/P1289 P0153EC-274
A/F SEN1 (B2) P1286 P0150EC-246
HO2S2HO2S2 (B1) P1146 P0138EC-297
HO2S2 (B1) P1147 P0137EC-286
HO2S2 (B1) P0139 P0139EC-310
HO2S2 (B2) P1166 P0158EC-297
HO2S2 (B2) P1167 P0157EC-286
HO2S2 (B2) P0159 P0159EC-310
EC-146
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TROUBLE DIAGNOSIS
Revision: 2006 January2006 M35/M45
Operation
1. “AUTO TRIG”
While trying to detect the DTC/1st trip DTC by performing the “DTC Confirmation Procedure”, be sure
to select to “DATA MONITOR (AUTO TRIG)” mode. You can confirm the malfunction at the moment it is
detected.
While narrowing down the possible causes, CONSULT-II should be set in “DATA MONITOR (AUTO
TRIG)” mode, especially in case the incident is intermittent.
When you are inspecting the circuit by gently shaking (or twisting) the suspicious connectors, compo-
nents and harness in the “DTC Confirmation Procedure”, the moment a malfunction is found the DTC/
1st trip DTC will be displayed. (Refer to “INCIDENT SIMULATION TESTS” in GI-28, "
How to Perform
Efficient Diagnosis for an Electrical Incident" .)
2. “MANU TRIG”
If the malfunction is displayed as soon as “DATA MONITOR” is selected, reset CONSULT-II to “MANU
TRIG”. By selecting “MANU TRIG” you can monitor and store the data. The data can be utilized for fur-
ther diagnosis, such as a comparison with the value for the normal operating condition.
Generic Scan Tool (GST) FunctionNBS004T8
DESCRIPTION
Generic Scan Tool (OBDII scan tool) complying with SAE J1978 has
8 different functions explained below.
ISO9141 is used as the protocol.
The name “GST” or “Generic Scan Tool” is used in this service man-
ual.
PBIB0197E
SEF139P
EC-160
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TROUBLE DIAGNOSIS - SPECIFICATION VALUE
Revision: 2006 January2006 M35/M45
10. DETECT MALFUNCTIONING PART
1. Check the following.
–Ignition coil and its circuit (Refer to EC-666, "IGNITION SIGNAL" .)
–Fuel injector and its circuit (Refer to EC-679, "FUEL INJECTOR" .)
–Intake air leakage
–Low compression pressure (Refer to EM-101, "CHECKING COMPRESSION PRESSURE" .)
2. If NG, repair or replace the malfunctioning part.
If OK, replace fuel injector. (It may be caused by leakage from fuel injector or clogging.)
>> GO TO 11.
11 . CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”
1. Start engine.
2. Select “A/F ALPHA-B1”, “A/F ALPHA-B2” in “DATA MONITOR (SPEC)” mode, and make sure that the
each indication is within the SP value.
OK or NG
OK >>INSPECTION END
NG >> GO TO 12.
12. CHECK A/F SENSOR 1 FUNCTION
Perform all DTC Confirmation Procedure related with A/F sensor 1.
For DTC P0130, P0150, refer to EC-246, "DTC Confirmation Procedure" .
For DTC P0131, P0151, refer to EC-256, "DTC Confirmation Procedure" .
For DTC P0132, P0152, refer to EC-265, "DTC Confirmation Procedure" .
For DTC P0133, P0153, refer to EC-275, "DTC Confirmation Procedure" .
For DTC P2A00, P2A03, refer to EC-655, "DTC Confirmation Procedure" .
OK or NG
OK >> GO TO 15.
NG >> GO TO 13.
13. CHECK A/F SENSOR 1 CIRCUIT
Perform Diagnostic Procedure according to corresponding DTC.
>> GO TO 14.
14. CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”
1. Start engine.
2. Select “A/F ALPHA-B1”, “A/F ALPHA-B2” in “DATA MONITOR (SPEC)” mode, and make sure that the
each indication is within the SP value.
OK or NG
OK >>INSPECTION END
NG >> GO TO 15.
15. DISCONNECT AND RECONNECT ECM HARNESS CONNECTOR
1. Stop the engine.
2. Disconnect ECM harness connector. Check pin terminal and connector for damage, and then reconnect it.
>> GO TO 16.
EC-182
[VQ35DE]
DTC P0031, P0032, P0051, P0052 A/F SENSOR 1 HEATER
Revision: 2006 January2006 M35/M45
DTC P0031, P0032, P0051, P0052 A/F SENSOR 1 HEATERPFP:22693
DescriptionNBS004U0
SYSTEM DESCRIPTION
The ECM performs ON/OFF duty control of the A/F sensor 1 heater corresponding to the engine operating
condition to keep the temperature of A/F sensor 1 element at the specified range.
CONSULT-II Reference Value in Data Monitor ModeNBS004U1
Specification data are reference values.
On Board Diagnosis LogicNBS004U2
DTC Confirmation ProcedureNBS004U3
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is between 10.5V and 16V at
idle.
WITH CONSULT-II
1. Turn ignition switch ON and select “DATA MONITOR” mode with
CONSULT-II.
2. Start engine and let it idle for at least 10 seconds.
3. If 1st trip DTC is detected, go to EC-186, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
Sensor Input Signal to ECM ECM function Actuator
Camshaft position sensor (PHASE)
Crankshaft position sensor (POS)Engine speed
Air fuel ratio (A/F) sensor 1
heater controlAir fuel ratio (A/F) sensor 1
heater
Mass air flow sensor Amount of intake air
MONITOR ITEM CONDITION SPECIFICATION
A/F S1 HTR (B1)
A/F S1 HTR (B2)
Engine: After warming up, idle the engine 0 - 100%
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0031
0031
(Bank 1)Air fuel ratio (A/F) sensor
1 heater control circuit
lowThe current amperage in the A/F sensor 1 heater
circuit is out of the normal range.
(An excessively low voltage signal is sent to ECM
through the A/F sensor 1 heater.)
Harness or connectors
(The A/F sensor 1 heater circuit is
open or shorted.)
A/F sensor 1 heater P0051
0051
(Bank 2)
P0032
0032
(Bank 1)Air fuel ratio (A/F) sensor
1 heater control circuit
highThe current amperage in the A/F sensor 1 heater
circuit is out of the normal range.
(An excessively high voltage signal is sent to ECM
through the A/F sensor 1 heater.)
Harness or connectors
(The A/F sensor 1 heater circuit is
shorted.)
A/F sensor 1 heater P0052
0052
(Bank 2)
SEF058Y
DTC P0037, P0038, P0057, P0058 HO2S2 HEATER
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DTC P0037, P0038, P0057, P0058 HO2S2 HEATERPFP:226A0
DescriptionNBS004U8
SYSTEM DESCRIPTION
The ECM performs ON/OFF control of the heated oxygen sensor 2 heater corresponding to the engine speed,
amount of intake air and engine coolant temperature.
OPERATION
CONSULT-II Reference Value in Data Monitor ModeNBS004U9
Specification data are reference values.
On Board Diagnosis LogicNBS004UA
Sensor Input signal to ECM ECM function Actuator
Camshaft position sensor (PHASE)
Crankshaft position sensor (POS)Engine speed
Heated oxygen sensor 2
heater controlHeated oxygen sensor 2 heater
Engine coolant temperature sensor Engine coolant temperature
Mass air flow sensor Amount of intake air
Engine speed rpm Heated oxygen sensor 2 heater
Above 3,600OFF
Below 3,600 rpm after the following conditions are met.
Engine: After warming up
Keeping the engine speed between 3,500 and 4,000 rpm for 1
minute and at idle for 1 minute under no loadON
MONITOR ITEM CONDITION SPECIFICATION
HO2S2 HTR (B1)
HO2S2 HTR (B2)
Engine speed: Below 3,600 rpm after the following conditions are met.
–Engine: After warming up
–Keeping the engine speed between 3,500 and 4,000 rpm for 1 minute and at
idle for 1 minute under no loadON
Engine speed: Above 3,600 rpm OFF
DTC No.Trouble diagnosis
nameDTC detecting condition Possible cause
P0037
0037
(Bank 1)Heated oxygen
sensor 2 heater
control circuit lowThe current amperage in the heated oxygen sen-
sor 2 heater circuit is out of the normal range.
(An excessively low voltage signal is sent to ECM
through the heated oxygen sensor 2 heater.)
Harness or connectors
(The heated oxygen sensor 2 heater circuit is
open or shorted.)
Heater oxygen sensor 2 heater P0057
0057
(Bank 2)
P0038
0038
(Bank 1)Heated oxygen
sensor 2 heater
control circuit highThe current amperage in the heated oxygen sen-
sor 2 heater circuit is out of the normal range.
(An excessively high voltage signal is sent to
ECM through the heated oxygen sensor 2
heater.)
Harness or connectors
(The heated oxygen sensor 2 heater circuit is
shorted.)
Heater oxygen sensor 2 heater P0058
0058
(Bank 2)
EC-206
[VQ35DE]
DTC P0101 MAF SENSOR
Revision: 2006 January2006 M35/M45
DTC Confirmation ProcedureNBS004UR
Perform PROCEDURE FOR MALFUNCTION A first.
If DTC cannot be confirmed, perform PROCEDURE FOR MALFUNCTION B.
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
PROCEDURE FOR MALFUNCTION A
NOTE:
If engine will not start or stops soon, wait at least 10 seconds with engine stopped (Ignition switch ON) instead
of running engine at idle speed.
With CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Start engine and warm it up to normal operating temperature.
4. Run engine for at least 10 seconds at idle speed.
5. If 1st trip DTC is detected, go to EC-209, "
Diagnostic Procedure"
.
With GST
Follow the procedure “With CONSULT-II” above.
PROCEDURE FOR MALFUNCTION B
CAUTION:
Always drive vehicle at a safe speed.
With CONSULT-II
1. Turn ignition switch ON.
2. Start engine and warm it up to normal operating temperature.
If engine cannot be started, go to EC-209, "
Diagnostic Procedure" .
3. Select “DATA MONITOR” mode with CONSULT-II.
4. Check the voltage of “MAS A/F SE-B1” with “DATA MONITOR”.
5. Increases engine speed to about 4,000 rpm.
6. Monitor the linear voltage rise in response to engine speed
increases.
If NG, go to EC-209, "
Diagnostic Procedure" .
If OK, go to following step.
SEF174Y
SEF243Y
DTC P0101 MAF SENSOR
EC-207
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Revision: 2006 January2006 M35/M45
7. Maintain the following conditions for at least 10 consecutive sec-
onds.
8. If 1st trip DTC is detected, go to EC-209, "
Diagnostic Procedure"
.
Overall Function CheckNBS004US
PROCEDURE FOR MALFUNCTION B
Use this procedure to check the overall function of the mass air flow sensor circuit. During this check, a DTC
might not be confirmed.
With GST
1. Start engine and warm it up to normal operating temperature.
2. Select Service $01 with GST.
3. Check the mass air flow sensor signal with Service $01.
4. Check for linear mass air flow sensor signal value rise in
response to increases to about 4,000 rpm in engine speed.
5. If NG, go to EC-209, "
Diagnostic Procedure" .
ENG SPEED More than 2,000 rpm
THRTL SEN 1 More than 3V
THRTL SEN 2 More than 3V
Selector lever Suitable position
Driving locationDriving vehicle uphill (Increased engine load) will help
maintain the driving conditions required for this test.
PBIB0199E
SEF534P