Fail-Safe Chart
WARNING: This page is about a different car, the 2007 Nissan Quest. However, it is still accessible from the selected car via links, so may be relevant.
When the DTC listed below is detected, the ECM enters fail-safe mode and the MIL lights up.
FAIL-SAFE CHART
| 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 temperature 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 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. |
|||
| (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. |
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| 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. |
|
- 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.
ENGINE OPERATING CONDITION - FAIL-SAFE MODE
| Engine operating condition in fail-safe mode | Engine speed will not rise more than 2, 500 rpm due to the fuel cut |