Infiniti Q45. Manual - part 362

TROUBLE DIAGNOSIS

EC-87

C

D

E

F

G

H

I

J

K

L

M

A

EC

Worksheet Sample

MTBL0017

EC-88

TROUBLE DIAGNOSIS

DTC Inspection Priority Chart

NBS002WF

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-156, "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-159, "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 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 ECM

●

P0643 Sensor power supply

●

P0700 TCM

●

P0705 Park/Neutral position (PNP) switch

●

P0850 Park/Neutral position (PNP) switch

●

P1610 - P1615 NATS

●

P2122 P2123 P2127 P2128 P2138 Accelerator pedal position sensor

TROUBLE DIAGNOSIS

EC-89

C

D

E

F

G

H

I

J

K

L

M

A

EC

2

●

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

●

P0452 P0453 EVAP control system pressure sensor

●

P0550 Power steering pressure sensor

●

P0603 ECM power supply

●

P0710 P0717 P0720 P0740 P0744 P0745 P1730 P1752 P1754 P1757 P1759 P1762 P1764 P1767 P1769 P1772 
P1774 A/T related sensors, solenoid valves and switches

●

P1140 P1145 Intake valve timing control position sensor

●

P1217 Engine over temperature (OVERHEAT)

●

P1220 Fuel pump control module

●

P1490 P1491 Vacuum cut valve bypass valve

●

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 - P0308 Misfire

●

P0420 P0430 Three way catalyst function

●

P0442 P0456 P1442 P1456 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

●

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

●

P1715 Turbine revolution sensor

●

P1800 VIAS control solenoid valve

●

P2119 Electric throttle control actuator

Priority

Detected items (DTC)

EC-90

TROUBLE DIAGNOSIS

Fail-Safe Chart

NBS002WG

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
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 time after turning 
ignition switch ON or START.
CONSULT-II displays the engine coolant temperature decided by ECM.

Condition

Engine coolant temperature decided 

(CONSULT-II display)

Just as ignition switch is turned 
ON or START

40

°

C (104

°

F)

More than approx. 4 minutes after 
ignition ON or START

80

°

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 
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
P2138

Accelerator pedal 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. 

Engine operating condition in fail-safe mode

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