DTC P1484 (LBS with M36 or LBY with M36)
Diagnostic Instructions
DTC Descriptor
| DTC P1484: Cooling Fan System Performance |
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
The ECM detects an over current at the output powerstage.
Action Taken When the DTC Sets
DTC P1484 is a Type A DTC.
Conditions for Clearing the DTC
DTC P1484 is a Type A DTC.
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
| 1. |
Verify that DTCs P0480, P0691
or P0962 are not present. |
| 2. |
Command the Cooling Fan
Increase and Decrease with the scan tool. Verify the cooling fan
operates as commanded. |
Circuit/System Testing
| 1. |
Ignition OFF, replace the G10
Cooling Fan Motor. |
| 2. |
Ignition ON, command the
Cooling Fan Increase and Decrease with the scan tool. Verify the
DTC does not reset. |
| ⇒ |
If the DTC resets, 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. |
|
