DTC C1186, C1266 [ABS]

id0402a7806100

DTC | C1186, C1266 | Fail-safe relay system
DETECTION CONDITION | • C1186 ― ABS HU/CM internal valve relay remains OFF when valve relay ON is commanded. • C1266 ― ABS HU/CM internal valve relay remains ON (stuck) when valve relay OFF is commanded.
POSSIBLE CAUSE | • ABS 30A fuse malfunction • Open circuit or short to ground in the wiring harness between the battery and the ABS HU/CM terminal C • Open or short circuit in the ABS HU/CM internal valve relay, or stuck valve relay • Poor connection at connectors (female terminal)

Diagnostic procedure

STEP | INSPECTION | ACTION
--- | --- | ---
1 | INSPECT ABS FUSE CONDITION • Is the ABS 30A fuse normal? | Yes | Go to the next step.
No | Replace the fuse, then go to Step 3.
2 | INSPECT VALVE RELAY POWER SUPPLY FOR OPEN CIRCUIT • Turn the ignition switch to the LOCK position. • Disconnect ABS HU/CM connector. • Turn the ignition switch to the ON position (engine off). • Measure voltage between ABS HU/CM terminal C (harness-side) and ground. • Is voltage B+? | Yes | Go to the next step.
No | Repair or replace the wiring harness for open circuit between battery positive terminal and ABS HU/CM terminal C, then go to the next step.
3 | VERIFY TROUBLESHOOTING COMPLETED • Clear the DTC from the memory. (See ON-BOARD DIAGNOSIS [ABS].) • Is the same DTC present? | Yes | Replace the ABS HU/CM, then go to next step. (See ABS HU/CM REMOVAL/INSTALLATION.)
No | Go to the next step.
4 | VERIFY AFTER REPAIR PROCEDURE • Are any other DTCs present? | Yes | Go to the applicable DTC inspection. (See ON-BOARD DIAGNOSIS [ABS].)
No | DTC troubleshooting completed.