For 1990-2009 cars

Step | Action | Yes | No
--- | --- | --- | ---
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle
2 | Test the engine coolant heater power supply cord for an open or short to ground. Refer to Circuit Testing . Did you find the 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 . Did you find the condition? | Go to Step 6 | Go to Step 5
5 | Replace the engine coolant heater. Refer to Coolant Heater Replacement . 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