Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Engine Cooling Schematics Connector End View Reference: Cooling System Connector End Views DEFINITION: The coolant by-pass valve does not move from the radiator flow position to the engine block flow position when the engine is started. | |||
1 | Did you perform the Engine Cooling Diagnostic System Check? | Go to Step 2 | |
2 | Start the engine while observing the coolant by-pass valve. Does the coolant by-pass valve move from the radiator flow position to the engine block flow position when the engine is started? | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | Go to Step 3 |
3 | With the engine still running, disconnect the vacuum hose from the coolant by-pass valve. Is there vacuum present at the hose? | Go to Step 12 | Go to Step 4 |
4 | Inspect the vacuum line from the by-pass solenoid to the by-pass valve for a restriction or damage. Did you find and correct the condition? | Go to Step 14 | Go to Step 5 |
5 | With the engine still running, disconnect the vacuum hose on the engine side of the coolant by-pass solenoid. Is there vacuum present at the hose? | Go to Step 6 | Go to Step 8 |
6 |
Does the test lamp illuminate? | Go to Step 7 | Go to Step 9 |
7 | Connect a test lamp between the ignition 1 voltage circuit and the ground circuit of the coolant by-pass solenoid harness connector. Does the test lamp illuminate? | Go to Step 11 | Go to Step 10 |
8 | Repair the damaged or blocked vacuum line that is causing a low vacuum condition between the coolant by-pass solenoid and the engine. Did you complete the repair? | Go to Step 14 | -- |
9 | Repair the open, short to ground, or high resistance in the ignition 1 voltage circuit of the coolant by-pass solenoid. Did you complete the repair? | Go to Step 14 | -- |
10 | Repair the open or high resistance in the ground circuit of the coolant by-pass solenoid. Did you complete the repair? | Go to Step 14 | -- |
11 | Inspect for poor connections at the harness connector of the coolant by-pass solenoid. 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 14 | Go to Step 13 |
12 | Replace the coolant by-pass valve. Refer to Coolant Bypass Valve Replacement . Did you complete the repair? | Go to Step 14 | -- |
13 | Replace the coolant by-pass solenoid. Refer to Coolant Bypass Solenoid Replacement . Did you complete the repair? | Go to Step 14 | -- |
14 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 2 |
