NO COLD START OR HOT RESTART DIAGNOSIS/PART NUMBER

COLD START OR HOT RESTART WHEN GLOW PLUG WAIT LAMP NOT OBSERVED

VEHICLES AFFECTED: 1983-89 6.2L DIESEL ALL C/K/R/V/G ------------------ AND P MODELS

Some customer comments have been received regarding no cold start capability or hot restart difficulty during intermittent engine temperature.

This can occur in cases of no cold start when the inhibit switch is not operating correctly. Reference service bulletin 88-662-100 for glow plug system diagnosis. Or in cases of hot restart difficulty, due to engine starting system degradation over time, the starting system is not at optimum performance, requiring glow plug assistance to start.

Replacement of the existing glow plug inhibit switch, P/N 15599010, with a service switch without a sensor, P/N 23504005 for model year 1983-87 LH6/LL4 and replacement of inhibit switch, P/N 23500830 with a service switch without a sensor, P/N 23504006 for model year 1988-89 LL4 only, allows glow plug assistance for enhanced startability.

Service Switch Without Sensor Installation

1. Disconnect batteries

2. Replacement service switch can be installed in exact location of the inhibit switch (with a socket wrench do not use open end wrench). Tighten to 19-27 N.m. (13-20 ft. lb.). Replace any lost coolant.

3. Connect glow plug inhibit switch connector assembly to service switch.

4. Reconnect batteries.

NOTICE: GLOW PLUG OPERATION (WAIT LAMP) WILL BE OBSERVED MORE FREQUENTLY ON THE HOT ENGINE RESTARTS WITH THE INSTALLATION OF THIS SERVICE SWITCH.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.