System Diagnostic Procedure

SOLID-STATE GLOW PLUG SYSTEM DIAGNOSTIC PROCEDURE
Perform the Glow Plug System Basic Diagnostic Test (hereafter referred to as Basic Test) first. If the vehicle passes the Basic Test without running any Pinpoint Tests, the Glow Plug system is OK and the vehicle's problem exists somewhere other than the Glow Plug System. However, if a step of the Basic Test fails, run only the Pinpoint Test specified by the failed step.

Glow Plug System Diagnostic Test Points:

Refer to the Glow Plug System Diagnostic Test Points image for test lamp connections and Glow Plug System wiring harness test points referred to in the Basic Test and the Pinpoint Tests. Perform only those services specified by the Pinpoint Tests.

Operation of the Glow Plug System is completely automatic. If after completing a specific Pinpoint Test it is determined that a component must be replaced, the glow plugs should be disconnected until the system has been re-checked by repeating the Basic Test to make sure the Glow Plug System works properly.

CAUTION: Never bypass the timed pulse function of the glow plug system. A constant 12 volt current to the glow plugs will cause them to overheat and fail within seconds, possibly resulting in severe engine damage.