Test Description
WARNING: This page is about a different car, the 2004 GMC Sierra, 2004 GMC Cab & Chassis Sierra, 2004 Chevrolet Silverado, and 2004 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
- 2: Be sure power supply cord is unplugged for 10 minutes prior to testing.
Coolant Heater Inoperative
| Step | Action | Yes | No |
|---|---|---|---|
| Connector End View Reference: Cooling System Connector End Views | |||
| 1 | Did you perform the necessary inspections? | Go to Step 2 | Go to Symptoms - Engine Cooling |
| 2 | Test the engine coolant heater power supply cord for an open or short to ground. Refer to Circuit Testing
in Wiring Systems. Did you find a condition? |
Go to Step 3 | Go to Step 4 |
| 3 | Replace the engine coolant heater power supply cord. Refer to Coolant Heater Cord Replacement . Did you complete the repair? |
Go to Step 6 | - |
| 4 | Inspect for poor connections at the harness connector of the engine coolant heater. Refer to Testing for Intermittent Conditions and Poor Connections
and Connector Repairs
in Wiring Systems. Did you find and correct the condition? |
Go to Step 6 | Go to Step 5 |
| 5 | Replace the engine coolant heater. Refer to Coolant Heater Replacement (4.3L) or Coolant Heater Replacement (4.8L, 5.3L, and 6.0L) or Coolant Heater Replacement (6.6L Engine) or Coolant Heater Replacement (8.1L) . Did you complete the repair? |
Go to Step 6 | - |
| 6 | Operate the system in order to verify the repair. Did you correct the condition? |
System OK | Go to Step 2 |