Buick Regal: DTC C1244, C1245, or C124B
Diagnostic Instructions
- Perform the Diagnostic System Check - Vehicle prior to using this
diagnostic procedure.
- Review Strategy Based Diagnosis for an overview of the diagnostic
approach.
- Diagnostic Procedure Instructions provides an overview of each
diagnostic category.
DTC Descriptors
DTC C1244
AWD Oil Pump Motor Speed Sensor Supply Circuit Low Voltage
DTC C1245
AWD Oil Pump Motor Speed Sensor Supply Circuit High Voltage
DTC C124B
AWD Oil Pump Motor Speed Sensor Signal Circuit Erratic
For symptom byte information, refer to Symptom Byte List.
Diagnostic Fault Information
Circuit/System Description
The rear differential clutch control module monitors the speed of the AWD oil
pump motor by using a hall effect
sensor which is internal to the differential clutch pump. The sensor is a
transducer that varies its output voltage in
response to a magnetic field.
Conditions for Running the DTC
C1244 00, C1245 00, C124B 00
- The engine is running.
- Battery voltage is between 9-16 V.
- The engine speed is above 400 rpm.
Conditions for Setting the DTC
C1244 00
The AWD oil pump motor speed sensor supply circuit voltage is below 1.0 V.
C1245 00
The AWD oil pump motor speed sensor supply circuit voltage is above 6.0 V.
C124B 00
A plausibility error is detected on the AWD oil pump motor speed sensor
signal circuit.
Action Taken When the DTC Sets
- Electronic limited slip is disabled for the duration of the key cycle.
- The AWD SERVICE message is displayed in the driver information center.
Conditions for Clearing the DTC
- The condition for the DTC is no longer present.
- The DTC is not detected in 40 consecutive ignition cycles.
Reference Information
Schematic Reference
Rear Axle Wiring Schematics
Connector End View Reference
COMPONENT CONNECTOR END VIEW INDEX
Description and Operation
Rear Drive Axle Description and Operation
Electrical Information Reference
- Circuit Testing
- Connector Repairs
- Testing for Intermittent Conditions and Poor Connections
- Wiring Repairs
Scan Tool Reference
Control Module References for scan tool information.
Circuit/System Testing
1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector
at the M32 Differential Clutch
Pump. It may take up to 2 min for all vehicle systems to power down.
2. Test for less than 10 Ω between the low reference circuit terminal 5 and
ground.
- Ignition OFF, disconnect the X2 harness connector at the K47 Rear
Differential Clutch Control Module.
- Test for less than 2 Ω in the low reference circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, replace the K47 Rear Differential Clutch Control
Module.
- Go to next step: If less than 10 Ω
3. Ignition ON/Vehicle in Service Mode.
4. Test for 4.8 - 5.2 V between the 5 V reference circuit terminal 1 and ground.
- Ignition OFF, disconnect the X2 harness connector at the K47 Rear
Differential Clutch Control Module.
- Test for infinite resistance between the 5 V reference circuit and
ground.
- If less than infinite resistance, repair the short to ground on the
circuit.
- Go to next step: If infinite resistance
- Test for less than 2 Ω in the 5 V reference circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, replace the K47 Rear Differential Clutch Control
Module.
- Ignition OFF, disconnect the X2 harness connector at the K47 Rear
Differential Clutch Control Module,
Ignition ON/Vehicle in Service Mode.
- Test for less than 1 V between the 5 V reference circuit and ground.
- If 1 V or greater, repair the short to voltage on the circuit.
- If less than 1 V, replace the K47 Rear Differential Clutch Control
Module.
Go to next step: If between 4.8 - 5.2 V
5. Test for 4.8 - 5.2 V between the signal circuit terminals listed below and
ground.
- Signal Circuit Terminal 2
- Signal Circuit Terminal 3
- Signal Circuit Terminal 4
- If less than 4.8 V
- Ignition OFF, disconnect the X2 harness connector at the K47 Rear
Differential Clutch Control Module.
- Test for infinite resistance between the appropriate signal circuit
terminal and ground.
- If less than infinite resistance, repair the short to ground on the
circuit.
- Go to next step: If infinite resistance
- Test for less than 2 Ω in the appropriate signal circuit terminal end to
end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, replace the K47 Rear Differential Clutch Control
Module.
- Ignition OFF, disconnect the X2 harness connector at the K47 Rear
Differential Clutch Control Module,
Ignition ON/Vehicle in Service Mode.
- Test for less than 1 V between the appropriate signal circuit terminal
and ground.
- If 1 V or greater, repair the short to voltage on the circuit.
- If less than 1 V, replace the K47 Rear Differential Clutch Control
Module.
- Go to next step: If between 4.8 - 5.2 V
6. Test or replace the M32 Differential Clutch Pump.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
- Differential Carrier Assembly Replacement
- Control Module References for control module replacement, programming
and setup.
READ NEXT:
Diagnostic Instructions
Perform the Diagnostic System Check - Vehicle prior to using this
diagnostic procedure.
Review Strategy Based Diagnosis for an overview of the diagnostic
approach.
Diag
Diagnostic Instructions
Perform the Diagnostic System Check - Vehicle prior to using this
diagnostic procedure.
Review Strategy Based Diagnosis for an overview of the diagnostic
approach.
Diag
Strategy Based Diagnostics
Review the system operations in order to familiarize yourself with the system
functions. Refer to Rear Drive Axle
Description and Operation, and Power Transfer Unit Case De
SEE MORE:
1. Crankshaft Balancer
WARNING: Refer to Safety Glasses Warning.
Procedure
Clean the crankshaft balancer.
Clean the belt grooves of all dirt or debris with a wire brush.
Dry the crankshaft balancer with compressed air.
Inspect the crankshaft balancer for the following:
Worn, grooved, or damag
If equipped, the FPB system may
help avoid or reduce the harm
caused by front-end crashes with
nearby pedestrians when driving in
a forward gear. FPB displays an
amber indicator, , when a nearby
pedestrian is detected directly
ahead. When approaching a
detected pedestrian too quickly,
FPB provides a