Chrysler Full-Size Trucks 1989-1996 Repair Guide

General Information


See Figures 1 and 2

The distributorless ignition system, used exclusively for the V10 engine, does not use a conventional mechanical distributor. It is otherwise very similar in function and operation to electronic ignitions found in other Plymouth/Dodge trucks and uses many similar components to the other trucks as well.

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Fig. Fig. 1: The Powertrain Control Module (PCM) is commonly located on the firewall-distributorless ignition system

The function normally handled by the distributor is given to the Powertrain Control Module (PCM) and an additional Ignition Control Module (ICM). The PCM is a computer containing a microprocessor that sends and receives signals to monitor and regulates engine operation. By controlling the coil ground circuit, the PCM is able to set base timing and adjust the ignition timing advance to meet changing engine operating conditions.

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Fig. Fig. 2: The Ignition Control Module (ICM) is mounted as shown-Ram trucks equipped with the V10 engine

The PCM advances or retards ignition timing based the transmission gear selection and on vital data signals it receives from the following sensors:

The Engine coolant temperature sensor
The Crankshaft position sensor
The Camshaft position sensor
The Manifold Absolute Pressure (MAP) sensor
The throttle position sensor