Pinpoint Test H: DTC C1266 - ABS Valve Power Relay Circuit Failure

WARNING: This page is about a different car, the 2009 Mercury Grand Marquis and 2009 Ford Crown Victoria. However, it is still accessible from the selected car via links, so may be relevant.

Refer to appropriate SYSTEM WIRING DIAGRAMS article, Vehicle Dynamic Systems for schematic and connector information.

Normal Operation

Fused battery voltage is provided to the ABS module from battery junction box (BJB) fuses 109 (20A) and 106 (40A) along circuits 483 (RD) and 601 (LB/PK) respectively. Fused ignition voltage is provided from central junction box (CJB) fuse 13 (10A) along circuit 1003 (GY/YE). When necessary, the ABS module supplies voltage to the hydraulic control unit (HCU) assembly and the pump motor is activated. The ABS module is provided a ground along circuit 57 (BK) and the hydraulic pump motor is provided a ground internally through the HCU.

DTC C1266 ABS Valve Power Relay Circuit Failure - If the ABS module detects an open circuit or a short to ground in the valve power circuit, DTC C1266 will be set.

This pinpoint test is intended to diagnose the following:

Fuse(s)
Wiring, terminals or connectors
ABS module

PINPOINT TEST H: DTC C1266 - ABS VALVE POWER RELAY CIRCUIT FAILURE

NOTE: The Flex Probe Kit must be used for all test connections. Use of standard multi-meter probes may damage wiring terminals.

H1 CHECK THE VOLTAGE TO THE ABS MODULE
- Disconnect: ABS module C135
- Measure the voltage between ABS module C135-14, circuit 483 (RD), harness side and ground.
- Is the voltage greater than 10 volts?
1. YES : INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module . TEST the system for normal operation.
2. NO : VERIFY BJB fuse 109 (20A) is OK. If OK, REPAIR circuit 483 (RD). CLEAR the DTCs. TEST the system for normal operation.