C0044-28

C0044-28-BRAKE PRESSURE SENSOR 1 - SIGNAL BIAS LEVEL OUT OF RANGE / ZERO ADJUSTMENT FAILURE

For a complete wiring diagram, refer to the Wiring Information.

- When Monitored:
Ignition on.

- Set Condition:
The Anti-lock Brake System (ABS) Module has detected brake pressure when the brake pedal has not been applied.





NOTE: Repair all other DTC's before continuing with this diagnostic procedure.

1. VERIFY THE DTC IS ACTIVE

NOTE: This DTC must be active for the results of this test to be valid.

1. Turn the ignition on.
2. With the scan tool, read and record DTCs.
3. With the scan tool, read and record Freeze Fame information.
4. With the scan tool, erase DTCs.
5. Start the engine.
6. Press the brake pedal firmly and release.
7. With the scan tool, read and record DTCs.

Is the DTC active at this time?

Yes

- Go To 2

No

- Perform the ABS INTERMITTENT CONDITION TEST. Testing and Inspection.

2. MECHANICAL BRAKE SYSTEM INSPECTION
1. Turn the ignition off.
2. Check the brake fluid for contaminants.
3. Visually inspect all the brake lines for bent, damaged, or pinched restrictions.

Where any problems found?

Yes

- Repair as necessary.
- Perform the ABS VERIFICATION TEST. ABS Verification Test.

No

- Go To 3

3. BRAKE PRESSURE
1. Start the engine.
2. The brake pedal released.
3. With the scan tool, under "Data Display" read the brake pressure.

Is the Brake Pressure below 10 bar (145 psi)?

Yes

- Go To 4

No

- Go To 5

4. BRAKE PEDAL INSPECTION
1. Turn the ignition off.
2. Check the brake pedal for damage or restrictions not allowing it to fully return.

Where any problems found?

Yes

- Repair as necessary.
- Perform the ABS VERIFICATION TEST. ABS Verification Test.

No

- Replace the Integrated Control Unit (ICU). Hydraulic Control unit (HCU) - Removal.
- Perform the ABS VERIFICATION TEST. ABS Verification Test.

5. BRAKE PEDAL POSITION (BPP) SENSOR
1. Start the engine.
2. With the scan tool, under "Data Display" monitor the brake switch and the brake pressure.
3. Press the brake pedal slowly.

Did the BPP sensor indicate pressed before their was brake pressure?

Yes

- Go To 6

No

- Replace the Brake Pedal Position (BPP) Sensor. Stop Lamp Switch - Removal.
- Perform the ABS VERIFICATION TEST. ABS Verification Test.

6. INTEGRATED CONTROL UNIT (ICU)
1. Test drive the vehicle.
2. With the scan tool, under "Data Display" read the brake pressure.
3. Without applying the brakes moderately accelerate the vehicle three to four times.

Was the Brake Pressure above 10 bar (145 psi)?

Yes

- NOTE: For this DTC it is necessary to replace both the ABS Module and the HCU as a complete unit.
- Replace the Integrated Control Unit (ICU). Hydraulic Control unit (HCU) - Removal.
- Perform the ABS VERIFICATION TEST. ABS Verification Test.

No

- Go To 7

7. ANTI-LOCK BRAKE SYSTEM (ABS) MODULE
1. Replace the Anti-Lock Brake System (ABS) Module. Anti-Lock Brake System Module - Removal.
2. Ignition on, engine not running.
3. With the scan tool, erase DTCs.
4. Start the engine.
5. Press the brake pedal firmly and release.
6. With the scan tool, read the DTCs.

Does the DTC remain active?

Yes

- Replace the Hydraulic Control Unit (HCU). Hydraulic Control unit (HCU) - Removal.
- Perform the ABS VERIFICATION TEST. ABS Verification Test.

No

- Test complete.