GM Service Manual Online
For 1990-2009 cars only

Test Description

  1. Be sure power supply cord is unplugged for 10 minutes prior to testing.

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

Important: The power supply cord will read open if the ambient temperature is above -1°F (-18°C).

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

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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 .

Did you complete the repair?

Go to Step 6

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6

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2