Pinpoint Test G: C1034:78

WARNING: This page is about a different car, the 2021 Ford F-150. However, it is still accessible from the selected car via links, so may be relevant.

G1 CARRY OUT THE ABS SELF TEST
- Ignition ON.
- Using a diagnostic scan tool, read the ABS DTC.
Is DTC C1034:78 set?

Yes GO to G2

No The system is operating correctly at this time.

G2 CHECK ABS (ANTI-LOCK BRAKE SYSTEM) MODULE PARK BRAKE STATUS PID (PARAMETER IDENTIFICATION)
- Using a diagnostic scan tool,
  Access the ABS and monitor the PBRKSTPID
- NOTE: Both Actuators should display the same state of Applied or Released.
  
  Apply and Release EPB while monitoring PBRKST PID.
Do both actuators match state?

Yes GO to G3

No GO to Pinpoint Test C

G3 VERIFY ALL WIRING CONNECTIONS

Ignition OFF.

Disconnect ABS module and the suspect parking brake actuator motor.

Using a good light source, inspect ABS module C135A, parking brake actuator motor C4478 or C4479 for the following:
- corrosion - install new connector or terminal and clean the module pins
- damaged or bent pins - install new terminals or pins
- pushed-out pins - install new pins as necessary
- spread terminals - install new terminals as necessary

Are the connectors free of corrosion, damaged pins, bent pins, pushed-out pins and spread terminals?

Yes

CHECK OASIS for any applicable service articles: TSB, GSB, SSM or FSA. If a service article exists for this concern, DISCONTINUE this test and FOLLOW the service article instructions. If no service articles address this concern, INSTALL a new ABS module. REFER to: Anti-Lock Brake System (ABS) Module .

No	REPAIR the connector or terminals. Refer to OEM CONNECTOR REPAIR PROCEDURES for schematic and connector information.