DTC P0480, P0691, or P0692 (LBS with M36, or LBY with M36)
Diagnostic Instructions
DTC Descriptors
| DTC P0480: Cooling Fan Relay 1 Control Circuit
Malfunction |
| DTC P0691: Cooling Fan Relay 1 Control Circuit
Low Voltage |
| DTC P0692: Cooling Fan Relay 1 Control Circuit
High Voltage |
Diagnostic Fault Information
Circuit
|
Short to Ground
|
Open/High Resistance
|
Short to Voltage
|
Signal Performance
|
Cooling Fan Motor Ignition B+
|
P0691
|
P0691
|
-
|
-
|
Cooling Fan Motor Ignition
|
1
|
1
|
-
|
-
|
Cooling Fan Motor Control
|
P0691
|
P0480
|
P0962
|
P1484
|
Cooling Fan Motor Ground
|
1
|
1
|
-
|
-
|
1. Fans Inoperative Without a DTC.
|
|
| |
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 speed controller included in
the cooling fan motor. The cooling fan speed controller supplies
the power and ground circuits for the cooling fan. The ECM sends a
pulse width modulated (PWM) signal to the cooling fan speed
controller. The cooling fan speed controller interprets the signal
and operates the cooling fan at the commanded speed.
Conditions for Running the DTC
| • |
The ignition voltage is
between 8-18 V. |
| • |
The engine is running greater
than or equal to 400 RPM. |
Conditions for Setting the DTC
P0480
The ECM detects a malfunction on the cooling fan relay 1 control
circuit.
P0691
The ECM detects a short to ground on the cooling fan relay 1
control circuit.
P0692
The ECM detects a short to voltage on the cooling fan relay 1
control circuit.
Action Taken When the DTC Sets
DTCs P0480, P0691 and P0692 are Type B DTCs.
Conditions for Clearing the DTC
DTCs P0480, P0691 and P0692 are Type B DTCs.
Reference Information
Schematic Reference
Engine Cooling Schematics
Connector End View Reference
Component Connector End Views
Description and Operation
Cooling System Description and Operation
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
Command the Cooling Fan Increase and Decrease with the scan
tool. Verify the cooling fan operates as commanded.
Circuit/System Testing
| 1. |
Ignition OFF, disconnect the
harness connector at the G10 Cooling Fan Motor. |
| 2. |
Verify that a test lamp
illuminates between the B+ circuit terminal 1 and ground.
|
| ⇒ |
If the test lamp does not illuminate, test the B+
circuit for a short to ground or an open/high resistance. |
| 3. |
Ignition ON, verify that a
test lamp does not illuminate between the control circuit terminal
3 and ground. |
| ⇒ |
If the test lamp illuminates, test the control
circuit for a short to voltage. If the circuit tests normal,
replace the K20 Engine Control Module. |
| 4. |
Ignition OFF, test for
infinite resistance between the control circuit terminal 3 and
ground. |
| ⇒ |
If less than the specified value, test the control
circuit for a short to ground. If the circuit tests normal, replace
the K20 Engine Control Module. |
| 5. |
Connect the harness connector
at the G10 Cooling Fan Motor, disconnect the X1 and X2 harness
connector at the K20 Engine Control Module. |
| 6. |
Test for greater than 11 V
between the control circuit terminal 91 X1 and ground. |
| ⇒ |
If less than the specified value, test the control
circuit for an open/high resistance. If the circuit tests normal,
replace the G10 Cooling Fan Motor. |
| 7. |
If all circuits test normal,
replace the K20 Engine Control Module. |
Repair Instructions
Perform the
Diagnostic Repair Verification after completing the diagnostic
procedure.
Repair Verification
| 1. |
Ignition ON, verify with a
scan tool that the ECM is not commanding fan activation.
|
| 2. |
Ignition ON, observe that the
fan is not activated. |
Ignition ON, verify with a scan tool that the ECM is not
commanding fan activation. Ignition ON, observe that the fan is not
activated.
|
