EC-90
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TROUBLE DIAGNOSIS
Revision: 2007 April2007 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-91
.
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-95
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-94
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TROUBLE DIAGNOSIS
Revision: 2007 April2007 M35/M45
10. DETECT MALFUNCTIONING PART BY DIAGNOSTIC PROCEDURE
Inspect according to Diagnostic Procedure of the system.
NOTE:
The Diagnostic Procedure in EC section described based on open circuit inspection. A short circuit inspection
is also required for the circuit check in the Diagnostic Procedure. For details, refer to Circuit Inspection in GI-
28, "How to Perform Efficient Diagnosis for an Electrical Incident" .
Is malfunctioning part detected?
Yes >> GO TO 11.
No >> Monitor input data from related sensors or check voltage of related ECM terminals using CON-
SULT-II. Refer to EC-138, "
CONSULT-II Reference Value in Data Monitor" , EC-114, "ECM Termi-
nals and Reference Value" .
11 . REPAIR OR REPLACE THE MALFUNCTIONING PART
1. Repair or replace the malfunctioning part.
2. Reconnect parts or connectors disconnected during Diagnostic Procedure again after repair and replace-
ment.
3. Check DTC. If DTC is displayed, erase it, refer to EC-68, "
HOW TO ERASE EMISSION-RELATED DIAG-
NOSTIC INFORMATION" .
>> GO TO 12.
12. FINAL CHECK
When DTC was detected in step 2, perform DTC Confirmation Procedure or Overall Function Check again,
and then make sure that the malfunction have been repaired securely.
When symptom was described from the customer, refer to confirmed symptom in step 3 or 4, and make sure
that the symptom is not detected.
OK or NG
NG (DTC*1 is detected)>>GO TO 10.
NG (Symptom remains)>>GO TO 6.
OK >> 1. Before returning the vehicle to the customer, make sure to erase unnecessary DTC*
1 in ECM
and TCM (Transmission Control Module). (Refer to EC-68, "
HOW TO ERASE EMISSION-
RELATED DIAGNOSTIC INFORMATION" and AT- 4 1 , "HOW TO ERASE DTC" .)
2. If the completion of SRT is needed, drive vehicle under the specific driving pattern. Refer to EC-
65, "Driving Pattern" .
3.INSPECTION END
*1: Include 1st trip DTC.
*2: Include 1st trip freeze frame data.
DIAGNOSTIC WORKSHEET
Description
There are many operating conditions that lead to the malfunction of
engine components. A good grasp of such conditions can make trou-
bleshooting faster and more accurate.
In general, each customer feels differently about a incident. It is
important to fully understand the symptoms or conditions for a cus-
tomer complaint.
Utilize a diagnostic worksheet like the one on the next page in order
to organize all the information for troubleshooting.
Some conditions may cause the MIL to come on steady or blink and
DTC to be detected. Examples:
Vehicle ran out of fuel, which caused the engine to misfire.
Fuel filler cap was left off or incorrectly screwed on, allowing fuel
to evaporate into the atmosphere.
SEF907L
EC-96
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TROUBLE DIAGNOSIS
Revision: 2007 April2007 M35/M45
DTC Inspection Priority ChartNBS004SZ
If some DTCs are displayed at the same time, perform inspections one by one based on the following priority
chart.
NOTE:
If DTC U1000 or U1001 is displayed with other DTC, first perform the trouble diagnosis for DTC
U1000, U1001. Refer to EC-161, "
DTC U1000, U1001 CAN COMMUNICATION LINE" .
If DTC U1010 is displayed with other DTC, first perform the trouble diagnosis for DTC U1010. Refer
to EC-164, "
DTC U1010 CAN COMMUNICATION" .
Priority Detected items (DTC)
1
U1000 U1001 CAN communication line
U1010 CAN communication
P0101 P0102 P0103 Mass air flow sensor
P0112 P0113 P0127 Intake air temperature sensor
P0117 P0118 P0125 Engine coolant temperature sensor
P0122 P0123 P0222 P0223 P1225 P1226 P2135 Throttle position sensor
P0128 Thermostat function
P0181 P0182 P0183 Fuel tank temperature sensor
P0327 P0328 Knock sensor
P0335 Crankshaft position sensor (POS)
P0340 P0345 Camshaft position sensor (PHASE)
P0460 P0461 P0462 P0463 Fuel level sensor
P0500 Vehicle speed sensor
P0643 Sensor power supply
P0605 ECM
P0700 TCM
P0705 P0850 Park/Neutral position (PNP) switch
P1550 P1551 P1552 P1553 P1554 Battery current sensor
P1610 - P1615 NATS
P2122 P2123 P2127 P2128 P2138 Accelerator pedal position sensor
TROUBLE DIAGNOSIS
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*: With ICC models2
P0031 P0032 P0051 P0052 Air fuel ratio (A/F) sensor 1 heater
P0037 P0038 P0057 P0058 Heated oxygen sensor 2 heater
P0075 P0081 Intake valve timing control solenoid valve
P0130 P0131 P0132 P0133 P0150 P0151 P0152 P0153 P2A00 P2A03 Air fuel ratio (A/F) sensor 1
P0137 P0138 P0139 P0157 P0158 P0159 Heated oxygen sensor 2
P0441 EVAP control system purge flow monitoring
P0443 P0444 P0445 EVAP canister purge volume control solenoid valve
P0447 P0448 EVAP canister vent control valve
P0451 P0452 P0453 EVAP control system pressure sensor
P0550 Power steering pressure sensor
P0603 ECM power supply
P0710 P0717 P0720 P0725 P0740 P0744 P0745 P1705 P1715 P1730 P1752 P1754 P1757 P1759 P1762 P1764
P1767 P1769 P1772 P1774 A/T related sensors, solenoid valves and switches
P1217 Engine over temperature (OVERHEAT)
P1220 Fuel pump control module
P1805 Brake switch
P2100 P2103 Throttle control motor relay
P2101 Electric throttle control function
P2118 Throttle control motor
3
P0011 P0021 Intake valve timing control
P0171 P0172 P0174 P0175 Fuel injection system function
P0300 - P0306 Misfire
P0420 P0430 Three way catalyst function
P0442 P0456 EVAP control system (SMALL LEAK, VERY SMALL LEAK)
P0455 EVAP control system (GROSS LEAK)
P0506 P0507 Idle speed control system
P1148 P1168 Closed loop control
P1211 TCS control unit
P1212 TCS communication line
P1421 Cold start control
P1564 ICC steering switch/ASCD steering switch
P1568 ICC command value*
P1572 ICC brake switch/ASCD brake switch
P1574 ICC vehicle speed sensor/ASCD vehicle speed sensor
P2119 Electric throttle control actuator Priority Detected items (DTC)
EC-98
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TROUBLE DIAGNOSIS
Revision: 2007 April2007 M35/M45
Fail-Safe ChartNBS004T0
When the DTC listed below is detected, the ECM enters fail-safe mode and the MIL lights up.
When there is an open circuit on MIL circuit, the ECM cannot warn the driver by lighting up MIL when
there is malfunction on engine control system.
Therefore, when electrical controlled throttle and part of ECM related diagnoses are continuously detected
as NG for 5 trips, ECM warns the driver that engine control system malfunctions and MIL circuit is open by
means of operating fail-safe function.
The fail-safe function also operates when above diagnoses except MIL circuit are detected and demands
the driver to repair the malfunction.
DTC No. Detected items Engine operating condition in fail-safe mode
P0102
P0103Mass air flow sensor circuit Engine speed will not rise more than 2,400 rpm due to the fuel cut.
P0117
P0118Engine coolant tempera-
ture sensor circuitEngine coolant temperature will be determined by ECM based on the time after turning
ignition switch ON or START.
CONSULT-II displays the engine coolant temperature decided by ECM.
ConditionEngine coolant temperature decided
(CONSULT-II display)
Just as ignition switch is turned
ON or START40°C (104°F)
More than approx. 4 minutes after
ignition ON or START80°C (176°F)
Except as shown above40 - 80°C (104 - 176°F)
(Depends on the time)
When the fail-safe system for engine coolant temperature sensor is activated, the cooling
fan operates while engine is running.
P0122
P0123
P0222
P0223
P2135Throttle position sensor The ECM controls the electric throttle control actuator in regulating the throttle opening in
order for the idle position to be within +10 degrees.
The ECM regulates the opening speed of the throttle valve to be slower than the normal
condition.
So, the acceleration will be poor.
P0643 Sensor power supply ECM stops the electric throttle control actuator control, throttle valve is maintained at a
fixed opening (approx. 5 degrees) by the return spring.
P2100
P2103Throttle control motor relay ECM stops the electric throttle control actuator control, throttle valve is maintained at a
fixed opening (approx. 5 degrees) by the return spring.
P2101 Electric throttle control
functionECM stops the electric throttle control actuator control, throttle valve is maintained at a
fixed opening (approx. 5 degrees) by the return spring.
P2118 Throttle control motor ECM stops the electric throttle control actuator control, throttle valve is maintained at a
fixed opening (approx. 5 degrees) by the return spring.
P2119 Electric throttle control
actuator(When electric throttle control actuator does not function properly due to the return spring
malfunction:)
ECM controls the electric throttle actuator by regulating the throttle opening around the
idle position. The engine speed will not rise more than 2,000 rpm.
(When throttle valve opening angle in fail-safe mode is not in specified range:)
ECM controls the electric throttle control actuator by regulating the throttle opening to 20
degrees or less.
(When ECM detects the throttle valve is stuck open:)
While the vehicle is driving, it slows down gradually by fuel cut. After the vehicle stops,
the engine stalls.
The engine can restart in N or P position, and engine speed will not exceed 1,000 rpm or
more.
P2122
P2123
P2127
P2128
P2138Accelerator pedal position
sensorThe ECM controls the electric throttle control actuator in regulating the throttle opening in
order for the idle position to be within +10 degrees.
The ECM regulates the opening speed of the throttle valve to be slower than the normal
condition.
So, the acceleration will be poor.
Engine operating condition in fail-safe mode Engine speed will not rise more than 2,500 rpm due to the fuel cut
EC-100
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TROUBLE DIAGNOSIS
Revision: 2007 April2007 M35/M45
1 - 6: The numbers refer to the order of inspection.
(continued on next page)Camshaft position sensor (PHASE) circuit 3 2EC-371
Vehicle speed signal circuit 2 3 3 3EC-468
Power steering pressure sensor circuit 2 3 3EC-474
ECM 22333333333EC-479,
EC-483
Intake valve timing control solenoid valve cir-
cuit32 13223 3EC-185
PNP switch circuit 3 3 3 3 3EC-491
Refrigerant pressure sensor circuit 2 3 3 4EC-704
Electrical load signal circuit 3EC-667
Air conditioner circuit 223333333 3 2AT C - 4 0
ABS actuator and electric unit (control unit) 4BRC-10
SYMPTOM
Reference
page
HARD/NO START/RESTART (EXCP. HA)
ENGINE STALL
HESITATION/SURGING/FLAT SPOT
SPARK KNOCK/DETONATION
LACK OF POWER/POOR ACCELERATION
HIGH IDLE/LOW IDLE
ROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEATS/WATER TEMPERATURE HIGH
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION
BATTERY DEAD (UNDER CHARGE)
Warranty symptom code AA AB AC AD AE AF AG AH AJ AK AL AM HA
TROUBLE DIAGNOSIS
EC-109
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EC
Revision: 2007 April2007 M35/M45
1. ECM 2. Data link connector 3. Accelerator pedal position sensor
4. Stop lamp switch 5. ICC brake switch
(models with ICC)
ASCD brake switch
(models with ASCD)6. ICC steering switch
(models with ICC)
ASCD steering switch
(models with ASCD)
7. RESUME/ACCELERATE switch 8. SET/COAST switch 9. CANCEL switch
10. DISTANCE switch
(ICC models only)11. MAIN switch
PBIB2680E
EC-114
[VQ35DE]
TROUBLE DIAGNOSIS
Revision: 2007 April2007 M35/M45
ECM Harness Connector Terminal LayoutNBS004T5
ECM Terminals and Reference ValueNBS004T6
PREPARATION
1. ECM (1) is located behind the passenger side instrument lower
panel. For this inspection, remove passenger side instrument
lower panel.
2. Remove ECM harness connector.
3. When disconnecting ECM harness connector, loosen (A) it with
levers (2) as far as they will go as shown in the figure.
ECM (1)
Fasten (B)
4. Connect a break-out box (SST) and Y-cable adapter (SST)
between the ECM and ECM harness connector.
Use extreme care not to touch 2 pins at one time.
Data is for comparison and may not be exact.
ECM INSPECTION TABLE
Specification data are reference values and are measured between each terminal and ground.
Pulse signal is measured by CONSULT-II.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECMs transistor. Use a ground other than ECM terminals, such as the ground.
MBIB0045E
PBIB2703E
PBIB2714E
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
1 B ECM ground[Engine is running]
Idle speedBody ground
2SBA/F sensor 1 heater
(bank 1)[Engine is running]
Warm-up condition
Idle speedApproximately 5V
PBIB1584E