Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
The instrument panel cluster (IPC) receives the engine speed information from the engine control module (ECM)/ powertrain control module (PCM) through the engine speed signal circuit. The ECM/PCM converts the data from the engine speed sensor to a (2 pulses)/(engine revolution) signal. The ECM/PCM also sends a class 2 message to the IPC indicating the engine speed.
• | Engine Controls Schematics for the 4.2L engine |
• | Engine Controls Schematics for the 5.3L engine |
⇒ | If the engine speed parameter does not match the tachometer display, test the signal circuit for a high resistance. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for the IPC replacement, setup, and programming