Pinpoint Test D : C1034:77, C2005:77, C2006:77
- Refer to VEHICLE DYNAMIC SYSTEMS
for schematic and connector information.
Normal Operation and Fault Conditions
When the ABS module receives a parking brake apply or release request, the ABS module sends voltage to the parking brake actuator motors. The ABS module also monitors the current draw of the actuator motors to determine when the brake pads contact the brake disc, to determine when the appropriate amount of clamping force is being applied to the brake disc and to determine when the brake pads are retracted to their start position. The actuator motors have a serviceable jumper harness connecting the actuator motor to the body harness at C334 for the LH actuator motor and C316 for the RH actuator motor.
DTC Fault Trigger Conditions
DTC Description Fault Trigger Condition ABS C1034:77 Park Brake: Commanded Position Not Reachable This DTC sets in continuous memory and on-demand if during an apply or release command, the ABS module detects an irregular current draw. ABS C2005:77 Right Actuator: Commanded Position Not Reachable This DTC sets in continuous memory and on-demand if during an apply or release command, the ABS module detects an irregular current draw. ABS C2006:77 Left Actuator: Commanded Position Not Reachable This DTC sets in continuous memory and on-demand if during an apply or release command, the ABS module detects an irregular current draw. Possible Sources
- Wiring, terminals or connectors
- Brake fluid leak
- Parking brake actuator motor
- Rear brake caliper
- D1 CHECK FOR OTHER ABS (ANTI-LOCK BRAKE SYSTEM) MODULE DIAGNOSTIC TROUBLE CODES (DTCS)
- Ignition ON.
- Using a diagnostic scan tool, carry out the ABS module self-test.
Is DTC C1034:77, C2005:74 or C2006:74 present?
Yes DIAGNOSE DTC C2005:74 or C2006:74 before diagnosing DTC C1034:77, C2005:77 or C2006:77. GO to Pinpoint Test C No If DTC C2005:77 or C2006:77 is present, GO to D2 For all other ABS module Diagnostic Trouble Codes (DTCs), GO to the Diagnostic Trouble Code (DTC) Chart . - D2 CHECK THE ACTUATOR MOTOR CIRCUITS FOR A SHORT TO GROUND
- Ignition OFF.
- Disconnect ABS module C155.
- Disconnect the suspect parking brake actuator motor electrical connector.
- For the RH actuator motor, measure:
Positive Lead Measurement / Action Negative Lead C4479-1 Ground C4479-2 Ground
- For the LH actuator motor, measure:
Positive Lead Measurement / Action Negative Lead C4478-1 Ground C4478-2 Ground
Are the resistances greater than 10, 000 ohms?
Yes GO to D3 No INSPECT the actuator motor jumper harness and connectors for correct routing, damaged connectors, spread terminals, bent or pushed-out pins or any signs of corrosion. INSTALL a new jumper harness as necessary. If the jumper harness is OK, REPAIR the circuit. - D3 CHECK THE ACTUATOR MOTOR CIRCUITS FOR A SHORT TOGETHER
- For the RH actuator motor, measure:
Positive Lead Measurement / Action Negative Lead C4479-1 C4479-2
- For the LH actuator motor, measure:
Positive Lead Measurement / Action Negative Lead C4478-1 C4478-2
Is the resistance greater than 10, 000 ohms?
Yes GO to D4 No INSPECT the actuator motor jumper harness and connectors for correct routing, damaged connectors, spread terminals, bent or pushed-out pins or any signs of corrosion. INSTALL a new jumper harness as necessary. If the jumper harness is OK, REPAIR the circuit. - For the RH actuator motor, measure:
- D4 CHECK THE ACTUATOR MOTOR CIRCUITS FOR AN OPEN
- For the RH actuator motor, measure:
Positive Lead Measurement / Action Negative Lead C4479-1 C155-12 C4479-2 C155-13
- For the LH actuator motor, measure:
Positive Lead Measurement / Action Negative Lead C4478-1 C155-3 C4478-2 C155-2
Are the resistances less than 3 ohms?
Yes GO to D5 No INSPECT the actuator motor jumper harness and connectors for correct routing, damaged connectors, spread terminals, bent or pushed-out pins or any signs of corrosion. INSTALL a new jumper harness as necessary. If the jumper harness is OK, REPAIR the circuit. - For the RH actuator motor, measure:
- D5 CHECK THE ACTUATOR MOTOR CIRCUITS FOR A SHORT TO VOLTAGENOTE: Performing this step sets Diagnostic Trouble Codes (DTCs) in the ABS module.
- Ignition ON.
- For the RH actuator motor, measure:
Positive Lead Measurement / Action Negative Lead C4479-1 Ground C4479-2 Ground
- For the LH actuator motor, measure:
Positive Lead Measurement / Action Negative Lead C4478-1 Ground C4478-2 Ground
Is any voltage present?
Yes INSPECT the actuator motor jumper harness and connectors for correct routing, damaged connectors, spread terminals, bent or pushed-out pins or any signs of corrosion. INSTALL a new jumper harness as necessary. If the jumper harness is OK, REPAIR the circuit. No GO to D6 - D6 INSPECT THE ACTUATOR MOTOR FOR EVIDENCE OF BRAKE FLUID OR WATER INTRUSION
- Ignition OFF.
- Remove the parking brake actuator motor. REFER to: Parking Brake Actuator Motor .
- Inspect the actuator motor and brake caliper for evidence of brake fluid leaks or water intrusion.
Is there any evidence of brake fluid leaks or water intrusion?
Yes If evidence of water intrusion is found, IDENTIFY and REPAIR the root cause. If evidence of a break fluid leak is found, INSTALL a new brake caliper and parking brake actuator motor assembly. REFER to: Parking Brake Actuator Motor . REFER to: Brake Caliper . No GO to D7 - D7 INSPECT THE BRAKE CALIPER FOR BRAKE FLUID LEAKS
- Clean any dirt or residue from the brake caliper.
- Apply and release the brake pedal.
- Inspect the brake caliper for signs of brake fluid leaks.
Are there any signs of brake fluid leaks?
Yes INSTALL a new rear brake caliper and parking brake actuator motor. REFER to: Parking Brake Actuator Motor . REFER to: Brake Caliper . No INSTALL a new parking brake actuator motor. REFER to: Parking Brake Actuator Motor .