PWM Fan

P0693-COOLING FAN 2 CONTROL CIRCUIT LOW (PWM FAN)





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

Theory of Operation

Vehicles with trailer tow packages are equipped with a pulse-width modulated (PWM) fan. Additionally, certain export market vehicles are also equipped with a PWM fan. The fan receives a duty cycle signal from the Totally Integrated Power Module (TIPM) on the (K175) Rad Fan High Speed Control circuit. Based on the requested fan speed from the PCM, the TIPM outputs a 10 Hz duty cycle signal on the (K175) Rad Fan High Speed Control circuit to the Radiator Cooling Fan. The Radiator Cooling Fan receives the duty cycle signal from the TIPM and controls the fan accordingly. The High Speed Cooling Fan Relay is not used to control any components and has no external function.

- When Monitored:
With the ignition on.

Battery voltage greater than 10 volts.

Cooling Fan off.

- Set Condition:
The TIPM detects an open or short to ground in the (K175) Rad Fan High Speed Control circuit.





1. CHECK FOR AN INTERMITTENT CONDITION
1. Turn the ignition on.
2. With the scan tool, clear all DTCs.
3. With the scan tool, read DTCs.

Does the scan tool display DTC: P0693-COOLING FAN 2 CONTROL CIRCUIT LOW?

Yes

- Go To 2

No

- Test complete, the condition or conditions that originally set this DTC are not present at this time. Using the wiring diagrams as a guide, check all related splices and connectors for signs of water intrusion, corrosion, pushed out or bent terminals, and correct pin tension.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

2. CHECK THE (K175) RAD FAN HIGH SPEED CONTROL CIRCUIT FOR AN OPEN IN THE HARNESS




1. Turn the ignition off.
2. Disconnect the TIPM C3 harness connector.
3. Disconnect the Radiator Cooling Fan Module harness connector.
4. Measure the resistance of the (K175) Rad Fan High Speed Control circuit between the TIPM C3 harness connector and Radiator Cooling Fan Module harness connector.

Is the resistance below 5.0 Ohms?

Yes

- Go To 3

No

- Repair the open or excessive resistance in the (K175) Rad Fan High Speed Control circuit.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

3. CHECK THE (K175) RAD FAN HIGH SPEED CONTROL CIRCUIT FOR A SHORT TO GROUND IN THE HARNESS




1. Turn the ignition off.
2. Measure the resistance between ground and the (K175) Rad Fan High Speed Control circuit at the Radiator Cooling Fan Module harness connector.

Is the resistance above 10k Ohms?

Yes

- Go To 4

No

- Repair the short to ground in the (K175) Rad Fan High Speed Control circuit.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

4. CHECK THE TIPM FOR CORRECT OPERATION





NOTE: Before continuing, check the TIPM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.

1. Reconnect the TIPM C3 harness connector.
2. Turn the ignition on.
3. Using a 12-volt test light connected to 12-volts, check the (K175) Rad Fan High Speed Control circuit.
4. With the scan tool, actuate the Radiator Fan 2 actuator using the On and Off commands.

Does the test light dimly blink on and off while Radiator Fan 2 is commanded on?

Yes

- Replace the Cooling Fan Module. Cooling Fan - Removal.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Replace the Totally Integrated Power Module. Totally Integrated Power Module (TIPM) - Removal.
- Perform the BODY VERIFICATION TEST. Body Verification Test.