Fail Safe Operation

FAIL-SAFE CHART
If any of the following codes is recorded, the engine control module (ECM) enters fail-safe mode.

CODE NUMBER: 14
Operation: Fuel Cut
Deactivation Conditions: 1 IGF signal detected in consecutive 2 (4) [1] ignition cycles.

CODE NUMBER: 16
Operation: Torque control prohibited.
Deactivation Conditions: Returned to normal condition.

CODE NUMBER: 22
Operation: Engine coolant temperature value (THW) is fixed at 80°C (176°F).
Deactivation Conditions: Returned to normal condition.

CODE NUMBER: 24
Operation: Intake air temperature value (THA) is fixed at 20°C (68°F).
Deactivation Conditions: Returned to normal condition.

CODE NUMBER: 31
Operation:
^ Ignition timing is fixed at 5° BTDC.
^ Injection time (duration) fixed at:
- Starting: 12.1 milliseconds
- IDL ON: 3.3 milliseconds
- IDL OFF: 6.1 milliseconds
^ Manifold absolute pressure is fixed at 46.7 kPa. (350 mmHg. 13.8 in.Hg)
Deactivation Conditions: Returned to normal condition.

CODE NUMBER: 41
Operation: Throttle position (VTA1) is fixed at 0°.
Deactivation Conditions: The following must each be repeated at least 2 times consecutively.
^ 0.1 V < VTA < 0.95 V
^ IDL: ON

CODE NUMBER: 52
Operation: Maximum timing retardation.
Deactivation Conditions: Ignition switch OFF.

BACK-UP FUNCTION
If there is trouble with the program in the engine control module (ECM) and the ignition signals (IGT) are not output from microcomputer, the ECM controls fuel injection and ignition timing at predetermined levels as a back-up function to make it possible to continue to operate the vehicle.
Furthermore, the injection duration is calculated from the starting signal (STA) and the throttle position signal (IDL). Also, the ignition timing is fixed at the initial ignition timing, 5° BTDC, without relation to the engine speed.

HINT: If the engine is controlled by the back-up function, the malfunction indicator lamp lights up to warn the driver of the malfunction but the diagnostic trouble code is not output.

[1] California specification vehicles (ONLY) use 4 consecutive ignition cycles