Powertrain Control Module (PCM)

P0692-COOLING FAN 1 CONTROL CIRCUIT HIGH





For a complete wiring diagram, refer to the Wiring Information.

Theory of Operation

The cooling fan is a hydro-electric controlled device that is engine mounted. The Powertrain Control Module (PCM) monitors various sensors to control fan speed. The cooling fan provides temperature control for engine coolant, engine charged air, A/C Freon and automatic transmission fluid. Fan speed increases as cooling requirements increase. Since the fan is mounted to the engine, fan speed is related to engine speed (RPM). The PCM uses a Pulse Width Modulated (PWM) driver to control the amount of fluid to the clutch fan. When the fan is fully engaged it is capable of speeds about 10% greater than engine speed. The fan will rotate anytime the engine is running, even when the PCM is not sending a PWM signal.

- When Monitored:
With the ignition on.

- Set Condition:
The Smart Power Relay is commanded on by the PCM, and feedback voltage is reading high.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.

1. ACTIVE DTC
1. Turn the ignition on.
2. Using the scan tool, record all Freeze frame data.
3. Using the scan tool, erase DTCs.
4. Turn the ignition off for 75 seconds.
5. Turn the ignition on.
6. Using the scan tool, actuate the Radiator Clutch Fan control on.
7. Using the scan tool, read DTCs.

Did the DTC reset?

Yes

- Go To 2

No

- Perform the INTERMITTENT CONDITION diagnostic procedure. Intermittent Condition Test

2. CHECK THE (K161) CLUTCH FAN SUPPLY CIRCUIT FOR A SHORT TO VOLTAGE
1. Stop actuation of the Radiator Clutch Fan.
2. Turn the ignition off.
3. Disconnect the Radiator Clutch Fan harness connector.

NOTE: Check connectors - Clean/repair as necessary.

4. Turn the ignition on.
5. Measure the voltage on the (K161) Clutch Fan Supply circuit at the Radiator Clutch Fan harness connector.

Is the voltage reading near battery voltage?

Yes

- Repair the (K161) Clutch Fan Supply circuit for a short to voltage.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Go To 3

3. CHECK THE (K161) CLUTCH FAN SUPPLY CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Turn the ignition off.
2. Disconnect the PCM C1 harness connector.

NOTE: Check connectors - Clean/repair as necessary.

3. Measure the resistance of the (K161) Clutch Fan Supply circuit between the PCM C1 harness connector and the Radiator Clutch Fan harness connector.

Is the resistance below 5.0 Ohms?

Yes

- Go To 4

No

- Repair the (K161) Clutch Fan Supply circuit for an open or high resistance.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

4. CHECK THE (K971) ACTUATOR GROUND CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Measure the resistance of the (K971) Actuator Ground circuit between the PCM C1 harness connector and the Radiator Fan harness connector.

Is the resistance below 5.0 Ohms?

Yes

- Go To 5

No

- Repair the (K971) Actuator Ground circuit for an open or high resistance.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

5. CHECK THE RADIATOR CLUTCH FAN
1. Measure the resistance between the (K161) Clutch Fan Supply circuit and the (K971) Actuator Ground circuit through the Radiator Clutch Fan.

Is the resistance between 6.0 and 10.0 Ohms?

Yes

- Replace the Powertrain Control Module.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Replace the Radiator Clutch Fan.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.