DTC P0480, P0691 or P0692 (LAU)
|
|
DTC P0480, P0691 or P0692 (LAU)
|
DTC P0480
Cooling Fan Speed Output Circuit
DTC P0691
Cooling Fan Speed Output Circuit Low Voltage
DTC P0692
Cooling Fan Speed Output Circuit High Voltage
|
Diagnostic Fault Information
|
|
Circuit
|
Short to Ground
|
Open/High Resistance
|
Short to Voltage
|
Signal Performance
|
|
Cooling Fan Control Module B+ Supply
|
P0480*
|
P0480
|
-
|
-
|
|
Cooling Fan Control Module Ground
|
-
|
-
|
-
|
-
|
|
Cooling Fan Control Module Control
|
P0691
|
P0480
|
P0692
|
-
|
|
*Opens cooling fan fuse.
|
|
Circuit/System Description
|
The engine control module (ECM) commands the cooling fan depending on cooling requirements. The ECM controls the cooling fan speed by commanding the cooling fan control module. The cooling fan control module supplies the power and ground circuits for the cooling fan. The ECM sends a pulse width modulated (PWM) signal to the cooling fan control module. The cooling fan control module interprets the signal and operates the cooling fan at the commanded speed.
|
Conditions for Running the DTC
|
|
•
|
The engine speed is greater than 0 RPM.
|
|
•
|
The ignition voltage is between 10-18 volts.
|
|
•
|
The DTCs run continuously once the above conditions are met.
|
|
Conditions for Setting the DTC
|
The ECM detects that the commanded state of the driver and the actual state of the control circuit do not match for greater than 1 second.
|
Action Taken When the DTC Sets
|
DTCs P0480, P0691, and P0692 are Type B DTCs.
|
Conditions for Clearing the MIL/DTC
|
DTCs P0480, P0691, and P0692 are Type B DTCs.
The ECM has the capability of providing command to the fan module even when a scan tool output control is being used. Always refer to the fan control command parameters on the scan tool to know when the fan is being commanded ON by the ECM.
Schematic Reference
Engine Cooling Schematics
Connector End View Reference
Component Connector End Views
Description and Operation
Cooling Fan Description and Operation (LF1)
Cooling Fan Description and Operation (LAU)
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References
for scan tool information
|
Circuit/System Verification
|
|
1.
|
|
Note
|
|
There is a slight delay before the cooling fans activate.
|
Ignition ON, command the cooling fan ON and OFF with a scan tool. The cooling fan should respond to the commanded states.
|
|
2.
|
Note the DTC information with a diagnostic tool. DTCs P0480, P0691 or P0692 should not set.
|
|
3.
|
Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
|
|
1.
|
Ignition OFF, disconnect the harness connector at the K22 cooling fan control module.
|
|
2.
|
Verify that a test lamp illuminates between the ground circuit terminal 2 and B+.
|
|
3.
|
If the test lamp does not illuminate, test the ground circuit for an open/high resistance.
|
|
4.
|
Ignition ON, verify that a test lamp illuminates between the B+ supply circuit terminal 1 and ground.
|
|
5.
|
If the test lamp does not illuminate, test the circuit for a short to ground or an open/high resistance. If the circuit tests normal and the B+ circuit fuse is open, test or replace the K22 cooling fan control module.
|
|
6.
|
|
Note
|
|
The cooling fan speed control circuit is pulled-up to a voltage within the ECM, 3-4 volts on the control circuit is normal.
|
Test for 3-4 V between the control circuit terminal 4 and ground.
|
|
7.
|
If less than the specified range, test the control circuit for an open or a short to ground. If the circuit tests normal, replace the K20 ECM.
|
|
8.
|
If greater than the specified range, test the control circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.
|
|
9.
|
Command the cooling fan ON and OFF with a scan tool. The DMM should transition from 3-4 V when commanded OFF to less than 1 V when commanded ON to more than 70%.
|
|
10.
|
If the circuit voltage does not correspond to the specified values, test the control circuit for a high resistance. If the circuit tests normal, replace the K20 ECM.
|
|
11.
|
If all circuits test normal, replace the K22 cooling fan control module.
|
Perform the
Diagnostic Repair Verification
after completing the diagnostic procedure.
