• Perform the Diagnostic System Check prior to using this diagnostic procedure:Diagnostic System Check - Vehicle
• Review the description of Strategy Based Diagnosis:Strategy Based Diagnosis
• An overview of each diagnostic category can be found here:Diagnostic Procedure Instructions

For an overview of the component/system, refer to:Cooling System Description and Operation

• { P30EE, P30EF }DTC U0632 = Not set
• Cooling Fan=Commanded On
• Ignition=On
• Ignition Voltage=Greater than 11 V
• { U0632 }Power Mode=Run

Frequency the DTC runs=Continuously—After the running conditions are met

Cooling Fan Speed¿Desired Cooling Fan Speed—For greater than 16 s

Cooling Fan Speed=Greater than 3,999 RPMorLess than a predefined threshold—For greater than 16 s

Cooling Fan Speed=Less than 110 RPM—For greater than 16 s

Serial Data circuit=Message Counter IncorrectFor greater than 1 s

Serial Data circuit=Message Counter IncorrectFor greater than 1 s

DTCs listed in the DTC Descriptor category=Type B DTC

DTCs listed in the DTC Descriptor category=Type B DTC

Engine Heating/Cooling Schematics

Component Connector End Views

• Circuit Testing
• Connector Repairs
• Testing for Intermittent Conditions and Poor Connections
• Wiring Repairs

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Control Module References

1. Ignition » On / Vehicle » In Service Mode

Note: This step only applies to the following component DTCs:Cooling Fan

2. Verify DTC U0632 is not set and no other DTCs are set.
• If DTC U0632 is set and no other DTCs are set

  Refer to: Circuit/System Testing

• If DTC U0632 is not set and other DTCs are set
3. Ignition/Vehicle » Off
4. Verify a condition does not exist with the component:
• Cooling Fan Motor—Binding or Sticking/Worn/Visible Damage
• Blade—Cracked/Foreign objects/Missing/Visible Damage
• If a condition exists

  Repair or replace as necessary

• If no condition exists
5. Ignition » On / Vehicle » In Service Mode
6. Perform the scan tool control function:Cooling Fan»Increase&Release Control

   Verify the component turns On and Off:Cooling Fan

• If the component does not turn On and Off

  Replace the component:K22 Cooling Fan Control Module

• If the component turns On and Off
7. Perform the scan tool control function:Cooling Fan»Increase&Decrease

   Verify the scan tool parameter:Cooling Fan Speed=Desired Cooling Fan Speed

• If not the specified state

  Refer to: Circuit/System Testing

• If the specified state
8. Perform the scan tool control function:Cooling Fan»Increase

   Verify a condition does not exist with the component:Cooling Fan—Turns Off

• Wiggle the harness and connector(s):G10 Cooling Fan Motor
• Wiggle the harness and connector(s):K20 Engine Control Module
• If a condition exists

  Repair as necessary » Wiring / Terminal(s) / Electrical Connector(s)

• If no condition exists
9. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

   Verify the DTC does not set.

• If the DTC sets

  Repeat step 2

• If the DTC is not set
10. All OK.

1. Ignition/Vehicle & All vehicle systems » Off
2. Disconnect the electrical connector:G10 Cooling Fan Motor
3. Test for less than 10 Ω between the test points:Ground terminal 1&Ground
• If greater than 10 Ω
1. Disconnect the ground connection:G106
2. Test for less than 2 Ω between the test points:Ground terminal 1&G106
• If 2 Ω or greater » Repair the open/high resistance in the circuit.
• If less than 2 Ω » Repair the open/high resistance in the ground connection.
• If less than 10 Ω
4. Ignition » On / Vehicle » In Service Mode
5. Verify a test lamp turns On between the test points:B+ circuit terminal 2&Ground
• If the test lamp does not turn On and the circuit fuse is OK
1. Ignition/Vehicle » Off & Remove » Test lamp
2. Test for less than 2 Ω between the test points:B+ circuit terminal 2&Output terminal@F4UB Fuse
• If 2 Ω or greater » Repair the open/high resistance in the circuit.
• If less than 2 Ω » Verify the fuse is OK and there is voltage at the fuse.
• If the test lamp does not turn On and the circuit fuse is open
1. Remove » Test Lamp
2. Test for infinite resistance between the test points:B+ circuit terminal 2&Ground
• If less than infinite resistance » Repair the short to ground on the circuit.
• If infinite resistance » Replace the component:G10 Cooling Fan Motor
• If the test lamp turns On
6. Test for 8 to 10 V between the test points:Serial Data circuit terminal 4@Component harness&Ground
• If less than 8 V
1. Ignition/Vehicle » Off
2. Disconnect the appropriate electrical connector:K20 Engine Control Module
3. Test for infinite resistance between the test points:Serial Data circuit terminal 4@Component harness&Ground
• If less than infinite resistance » Repair the short to ground on the circuit.
• If infinite resistance
4. Test for less than 2 Ω between the test points:Serial Data circuit terminal 4@Component harness&The other end of the circuit@Control module harness
• If 2 Ω or greater » Repair the open/high resistance in the circuit.
• If less than 2 Ω » Replace the component:K20 Engine Control Module
• If greater than 10 V
1. Ignition/Vehicle » Off
2. Disconnect the appropriate electrical connector:K20 Engine Control Module
3. Ignition » On / Vehicle » In Service Mode
4. Test for less than 1 V between the test points:Serial Data circuit terminal 4@Component harness&Ground
• If 1 V or greater » Repair the short to voltage on the circuit.
• If less than 1 V » Replace the component:K20 Engine Control Module
• If between 8 and 10 V
7. Test or replace the component:G10 Cooling Fan Motor

Perform the Diagnostic Repair Verification after completing the repair:Diagnostic Repair Verification

• Engine Coolant Fan Replacement—G10 Cooling Fan Motor
• For control module replacement, programming, and setup refer to:Control Module References