C1266

C1266-1 CHECK ABS VALVE POWER CIRCUIT VOLTAGE
- Disconnect connector C1057 from Anti-lock brake module. Connect breakout box and adapter to the harness connector C1057.
- Measure the voltage between Pin 13 and a known good ground.
- Is there a minimum of 10 volts?
YES - DTC C1266 diagnosis completed. Restore Vehicle. Retest System.
No - Go to C1266-2.

C1266-2 CHECK ABS MODULE GROUND FOR OPEN CIRCUIT
- With breakout box adapter disconnected from anti-lock brake control module and connected to harness,
- Using an ohmmeter, measure resistance between breakout box Pin 13 and a known good ground.
- Is resistance less than 5 ohms?
YES - Go to C1266-3
No - Service Circuit 570 (BK/W) for an open. Restore vehicle. Retest system.

C1266-3 CHECK ABS VALVE POWER CIRCUIT FOR SHORT TO GROUND
- At power distribution box, carefully remove and inspect Fuse 18 (30A).
- Using an ohmmeter, measure resistance between breakout box Pin 13 and a known good ground.
- Is resistance less than 10K ohms?
YES - Service Circuit 533 (T/R) for a short to ground. Replace Fuse 18 (30A) with a new fuse. Restore vehicle. Retest system.
No - Go to C1266-4

C1266-4 CHECK ABS VALVE POWER FEED CIRCUIT FOR OPEN
- USing an ohmmeter, check resistance between fuse 18 (30A) and pin 13 of the breakout box.
- IS RESISTANCE LESS THAN 5 OHMS?
YES - Replace Ant-lock control module. Restore vehicle. Retest system.
No - Service Circuit 533 (T/R) for an open. Restore vehicle. Retest System.