C1073

C1073 - Anti Lock Brake System Pump Motor Control Circuit






For a complete wiring diagram, refer to.

• When Monitored: With the ignition ON.

• Set Condition: The ABS module detects LOW pump motor feedback voltage with actuation of the pump motor relay.






Test Step 1 - Test for A DTC C1073-ABS Pump Motor Control Circuit

• This DTC must be active for the results of this test to be valid. If present, diagnose and repair DTC C2116-ABS Pump Motor Supply LOW Voltage before diagnosing this DTC.

• Turn the ignition ON.

• With the scan tool, record and erase DTCs.

• Cycle the ignition switch from OFF to ON.

• Road test the vehicle over 40 km/h (25 m.p.h.).

• Vehicle must be driven more than 40 km/h (25 m.p.h.) for set conditions to be meet.

• With the scan tool, read DTCs.

• The anti lock brake module must sense ALL 4 wheels at 12 km/h (7.5 m.p.h.) before it will extinguish the ABS indicators.

Does the scan tool display C1073 - ABS Pump Motor Control Circuit?

Yes

• Go to Test Step 2 => [ Test Step 2 - Test the ABS Pump Motor Fused B+ for an Open ]

No

• Refer to the Intermittent Condition diagnostic procedure.

Test Step 2 - Test the ABS Pump Motor Fused B+ for an Open

• Turn the ignition OFF.

• Remove and visually inspect the ABS pump motor B+ fuse.

Is the ABS Pump Motor B+ fuse open?

Yes

• Go to Test Step 3 => [ Test Step 3 - Test the Fused B(+) for a Short to Ground ]

No

• Go to Test Step 5 => [ Test Step 5 - Test the Voltage on the Fused B(+) Circuit ]

Test Step 3 - Test the Fused B(+) for a Short to Ground






• Disconnect the anti lock brake module harness connector.

• Using a 12 volt test lamp connected to 12 volts, probe the fused B+ circuit.

Does the test lamp illuminate brightly?

Yes

• Repair the fused B(+) circuit for a short to ground.

• Perform ABS Verification Test. Refer to => Non-DTC
Based Diagnostics. ABS Verification Test

No

• Go to Test Step 4 => [ Test Step 4 - Test the Fused B(+) Circuit ]

Test Step 4 - Test the Fused B(+) Circuit

• Visually inspect the fused B(+) circuit in the wiring harness.

• Look for any signs of intermittent short to ground.

Is the wiring harness OK?

Yes

• Go to Test Step 5 => [ Test Step 5 - Test the Voltage on the Fused B(+) Circuit ]

No

• Repair the fused B(+) circuit for a short to ground.

• Perform ABS Verification Test. Refer to => Non-DTC
Based Diagnostics. ABS Verification Test

Test Step 5 - Test the Voltage on the Fused B(+) Circuit






• Disconnect the anti lock brake module harness connector.

• Measure the voltage of the fused B(+) circuit in the anti lock brake module harness connector.

Is the voltage more than 10 volts?

Yes

• Go to Test Step 6 => [ Test Step 6 - Test the Ground Circuit for an Open ]

No

• Repair the fused B(+) circuit for an open.

• Perform ABS Verification Test. Refer to => Non-DTC
Based Diagnostics. ABS Verification Test

Test Step 6 - Test the Ground Circuit for an Open






• Measure the resistance of the ground circuit between the anti lock brake module harness connector and ground

Is the resistance less than 5.0 ohms?

Yes

• Replace the ICU.

• Perform ABS Verification Test. Refer to => Non-DTC
Based Diagnostics. ABS Verification Test

No

• Repair the high resistance in the affected circuit.

• Perform ABS Verification Test. Refer to => Non-DTC
Based Diagnostics. ABS Verification Test