Coolant Temperature Indicator
WARNING: This page is about a different car, the 1994 Pontiac Bonneville. However, it is still accessible from the selected car via links, so may be relevant.
- Turn ignition on. If indicator light does not come on, go to next step. If indicator light comes on, start engine and check indicator light. If indicator remains on, go to step 4). If indicator goes out, check sensor resistance. See COOLANT TEMPERATURE SENSOR RESISTANCE SPECIFICATIONS table. Replace sensor if resistance is not correct.
- Backprobe test light between Green PCM connector terminal C7 (Pink/Black wire) and battery voltage. If test light comes on, go to next step. If test light does not come on, check for poor connection at PCM. If connection is okay, replace PCM.
- Backprobe test light between IPC connector terminal A1 (Pink/Black wire) and battery voltage. See Figure to 3. If test light does not come on, repair open in Pink/Black wire. If test light comes on, check for poor connection at IPC or blown indicator bulb. If bulb and connection are okay, replace IPC.
- If coolant temperature is less than 255°F (124°C), go to next step. If coolant temperature is greater than 255°F (124°C), check sensor resistance. See COOLANT TEMPERATURE SENSOR RESISTANCE SPECIFICATIONS table. Replace sensor if resistance is not correct.
- Turn ignition off. Disconnect Green PCM connector. Turn ignition on. Connect a test light between battery voltage and PCM connector terminal C7 (Pink/Black wire). If test light comes on, repair short to ground in Pink/Black wire between instrument panel and PCM. If test light does not come on, replace PCM.
COOLANT TEMPERATURE SENSOR RESISTANCE SPECIFICATIONS
| Temperature °F (°C) | Ohms |
|---|---|
| 212 (100) | 177 |
| 194 (90) | 241 |
| 176 (80) | 332 |
| 158 (70) | 467 |
| 140 (60) | 667 |
| 122 (50) | 973 |
| 104 (40) | 1459 |
| 86 (30) | 2238 |
| 68 (20) | 3520 |
| 50 (10) | 5670 |
| 32 (0) | 9420 |
| 14 (-10) | 16,180 |
| -4 (-20) | 28,680 |
| -22 (-30) | 52,700 |
| -40 (-40) | 100,700 |