MODEL IDENTIFICATION
Vehicle model is identified by fifth character of Vehicle Identification Number (VIN), stamped on metal pad on top of left end of instrument panel, near windshield. See MODEL IDENTIFICATION table.
| Series (1) | Model |
|---|---|
| "C" | 2WD Pickup, Sierra & Suburban |
| "G" | RWD Van |
| "K" | 4WD Blazer, Pickup, Sierra, Suburban & Yukon |
| "L" | All-Wheel Drive Astro & Safari |
| "M" | 2WD Astro & Safari |
| "P" | Commercial Van/Motorhome |
| "S" | 2WD Blazer, Jimmy, Pickup & Sonoma |
| "T" | Bravada, 4WD Blazer, Jimmy, Pickup, Sonoma & Typhoon |
| "U" | Lumina APV, Silhouette & Trans Sport |
| (1) Vehicle series is fifth character of VIN. | |
| (1) | Vehicle series is fifth character of VIN. |
MODEL IDENTIFICATION
NORMAL GLOW PLUG CIRCUIT OPERATION
A normal functioning system should operate as follows
- With ignition switch in ON position, engine not running and at room temperature, glow plugs are on for 4-6 seconds, then off for about 4.5 seconds. Following this on-and-off cycle, glow plugs are on for about 1.5 seconds and off for about 4.5 seconds. The glow plugs continue to cycle on and off in this time sequence for about 20 seconds.
- If engine is cranked during or after the above sequence, glow plugs will cycle on and off for a total duration of 25 seconds after ignition switch is returned from crank position, whether engine starts or not. Engine does not have to be running to terminate glow plug cycling.
Note. Glow plug on-and-off times vary with engine temperature, system voltage and/or ambient temperature. Lower temperatures cause longer duration of cycling.