Test Description
Number(s) below refer to the step number(s) on the Diagnostic Table.
- This step, along with Step 5, checks for the ability of the ECM to operate the cooling fans.
- This step, along with Step 9, checks for the ability of the ECM to operate the cooling fans in response to A/C pressure readings.
- After confirming battery voltage and the ECM supplying a ground to the coil side of the cooling fan relay A, by jumpering connector terminals 30 and 87 it will be determined if the relay is at fault or a wiring problem is present.
- This step checks for the presence of battery voltage to the main cooling fan when the A/C is ON. If battery voltage is present and the cooling fans are not operating, the problem is in the ground side of the cooling fan circuit.
- By directly grounding the ECM connector terminals C50 and E34, the main and auxiliary cooling fans should run at high speed.