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Infiniti QX56 (JA60). Manual - part 451

EC-456

< ECU DIAGNOSIS >

[VK56DE]

ECM

Fail-Safe Chart

INFOID:0000000005149496

When the DTC listed below is detected, the ECM enters fail-safe mode and the MIL lights up.

AABIA0046GB

ECM

EC-457

< ECU DIAGNOSIS >

[VK56DE]

• 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
P0103

Mass air flow sensor circuit Engine speed will not rise more than 2,400 rpm due to the fuel cut.

P0117
P0118

Engine coolant tempera-
ture sensor circuit

Engine coolant temperature will be determined by ECM based on the following condition.
CONSULT-IIl displays the engine coolant temperature decided by ECM.

Condition

Engine coolant temperature decided

(CONSULT-IIl display)

Just as ignition switch is turned ON
or START

°C (104°F)

Approx 4 minutes or more after en-
gine starting.

°C (176°F)

Except as shown above

40 - 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
P2135

Throttle 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
P2103

Throttle 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
function

ECM 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 ac-
tuator

(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
P2138

Accelerator pedal position
sensor

Engine operating condition in fail-safe mode

Engine speed will not rise more than 2,500 rpm due to the fuel cut

EC-458

< ECU DIAGNOSIS >

[VK56DE]

ECM

DTC Inspection Priority Chart

INFOID:0000000005149497

If some DTCs are displayed at the same time, perform inspections one by one based on the following priority

chart.

Priority

Detected items (DTC)

• U0101 CAN communication line
• U1001 CAN communication line
• P0101 P0102 P0103 Mass air flow sensor
• P0112 P0113 P0127 Intake air temperature sensor
• P0116 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 P0332 P0333 Knock sensor
• P0335 Crankshaft position sensor (POS)
• P0340 Camshaft position sensor (PHASE)
• P0460 P0461 P0462 P0463 Fuel level sensor
• P0500 Vehicle speed sensor
• P0605 P0607 ECM
• P0643 Sensor power supply
• P0700 TCM
• P0705 Park/neutral position (PNP) switch
• 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

• 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 P0731 P0732 P0733 P0734 P0735 P0740 P0744 P0745 P1730 P1752 P1757 P1762 P1767

P1772 P1774 A/T related sensors, solenoid valves and switches

• P1217 Engine over temperature (OVERHEAT)
• P1140 P1145 Intake valve timing control position sensor
• P1805 Brake switch
• P2100 P2103 P2118 Electric throttle control actuator
• P2101 Electric throttle control function

• P0011 P0021 Intake valve timing control
• P0171 P0172 P0174 P0175 Fuel injection system function
• P0300 - P0308 Misfire
• P0420 P0430 Three way catalyst function
• P0442 EVAP control system (SMALL LEAK)
• P0455 EVAP control system (GROSS LEAK)
• P0456 EVAP control system (VERY SMALL 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/ASCD steering switch
• P1568 ICC command value
• P1572 ICC/ASCD brake switch
• P1574 ICC/ASCD vehicle speed sensor
• P2119 Electric throttle control actuator