Code Description

NOTE: After each service or repair procedure has been completed, reconnect all components. Clear DTCs and repeat QUICK TEST procedures to ensure all electronic engine control systems are working properly and DTCs are no longer present.

This test is for models with Calif. emissions only. Perform this test when directed by QUICK TEST. The glow plug system is composed of solid state Glow Plug Control Module (GPCM), glow plugs and associated wiring. Glow plug "on" time is controlled by Powertrain Control Module (PCM) and is a function of engine oil temperature, barometric pressure and battery voltage. Glow plug "on" time varies between 1-120 seconds. In addition to PCM control, the GPCM internally limits glow plug operation to 180 seconds regardless of PCM commanded "on" time. Power to glow plugs is provided though the GPCM solid state drivers directly from the battery. Failures detected by the GPCM are passed to the PCM using a serial communication signal. This test is only intended to diagnose the following components and circuits.

Glow Plugs
GPCM
Engine And Chassis Wiring Harness
Under Valve Cover (UVC) Wiring Harness
PCM
CAUTION: Connectors are not interchangeable. If connectors are mismatched, a DTC will be generated. Ensure Green harness connector is plugged into Green GPCM connector, and Black harness connector is plugged into Black GPCM connector. Black stripe on GPCM housing should align with Black harness connector.