Deceleration Mode

When the engine is at operating temperature, this is an Open Loop mode. During hard deceleration, the PCM receives the following inputs.

1. Air conditioning select signal (if equipped)
2. Air conditioning request signal (if equipped)
3. Battery voltage
4. Engine coolant temperature sensor
5. Crankshaft position sensor
6. Intake manifold air temperature sensor
7. Manifold absolute pressure (MAP) sensor
8. Throttle position sensor (TPS)
9. Camshaft position sensor signal
10. Park/neutral switch (gear indicator signal-auto. trans. only)
11. Vehicle speed

If the vehicle is under hard deceleration with the proper RPM and closed throttle conditions, the PCM will ignore the oxygen sensor input signal. The PCM will enter a fuel cut-off strategy in which it will not supply a ground to the injectors. If a hard deceleration does not exist, the PCM will determine the proper injector pulse width and continue injection.

The PCM adjusts ignition timing by turning the ground path to the coils on and off.