Deceleration Mode

WARNING: This page is about a different car, the 2003 Dodge Intrepid, 2003 Chrysler Intrepid, 2003 Chrysler Concorde, and 2003 Chrysler 300M. However, it is still accessible from the selected car via links, so may be relevant.

This is a CLOSED LOOP mode. During deceleration the following inputs are received by the PCM:

A/C Status
Battery Voltage
Inlet/Intake Air Temperature
Engine Coolant Temperature
Crankshaft Position (Engine Speed)
Exhaust Gas Oxygen Content (Upstream Heated Oxygen Sensor)
Knock Sensor
Manifold Absolute Pressure
Throttle Position Sensor
IAC motor (solenoid) control changes in response to MAP sensor feedback.

The PCM may receive a closed throttle input from the (TP) sensor when it senses an abrupt decrease in manifold pressure. This indicates a hard deceleration (Open Loop). In response, the PCM may momentarily turn off the injectors. This helps improve fuel economy, emissions and engine braking.