DESCRIPTION
Charging system consists of a 110-amp generator, internal voltage regulator, battery, Powertrain Control Module (PCM), charge warning indicator, related fuses and wiring. PCM determines optimal voltage setpoint for charging system and communicates information to voltage regulator. PCM and generator communicate by using 2 uni-directional communication lines. Both of these communication lines are pulse-width modulated. An GEN COM line communicates desired setpoint from PCM to voltage regulator. An GEN MON line communicates alternator load condition to PCM. A third terminal on voltage regulator is a dedicated battery voltage sense line.
Charge warning indicator should illuminate with ignition on, engine off. Charge warning indicator should not illuminate with ignition off, or with engine running. Generator and regulator cannot be serviced separately, and must be replaced as an assembly.
KOEO on-demand self-test is a functional test of PCM performed with ignition switch turned to ON position, engine off. This test checks if PCM inputs and outputs are functioning electronically without any faults. A fault must be present at time of testing for KOEO on-demand self-test to detect a fault.
KOER on-demand self-test is a functional test of PCM performed with ignition key on, engine running. A check of certain inputs and outputs is made during operating conditions and normal operating temperature. The Brake Pedal Position (BPP) switch, Power Steering Pressure (PSP) switch and Transmission Control Switch (TCS) tests are part of KOER on-demand self-test and must be performed during this operation (if applicable). See BPP, PSP & TCS TEST PROCEDURES . A fault must be present at time of testing for KOER on-demand self-test to detect a fault.
Continuous memory self-test is a functional test of PCM performed under any condition (engine running or engine off) with ignition switch turned to ON position. Unlike KOEO and KOER self-tests which can only be activated on demand, continuous monitor is always active in monitoring the system. When a fault is detected, DTC will be stored in memory. This makes it possible to diagnose intermittent faults.
There are 2 types of Continuous Memory DTCs. Emission related DTCs will illuminate the Malfunction Indicator Light (MIL) on instrument cluster. Non-emission DTCs will never illuminate MIL. On emission-related MIL codes, PCM will store DTC in continuous memory at first detection of concern. The MIL will not be illuminated, but DTC is considered by PCM to be a pending DTC. If same concern is detected in next drive cycle, MIL will illuminate. MIL will go out if fault is not present after 3 consecutive drive cycles, or PCM has been reset. An emission-related pending DTC or non-emission DTC will be erased after 40-80 warm-up cycles or PCM reset.