ABS Inlet Valve Circuit Short to Ground
The C1257 code indicates that the Skid Control ECU has detected a short to ground in the inlet valve solenoid circuit for the right rear wheel. This fault disables the ABS, VSC, and traction control systems, and triggers the corresponding warning lights on the dashboard.
1. Commonly Affected Makes
2. Most Common Causes
- Short to ground in the wiring harness between the Skid Control ECU and the hydraulic actuator (ABS unit)
- Internal failure of the right rear inlet valve solenoid within the hydraulic actuator
- Damaged, corroded, or chassis-grounded terminals at the hydraulic actuator or ECU connector
- Internal failure of the Skid Control ECU (valve driver circuit)
3. Symptoms You Will Notice
- ABS warning light illuminated
- VSC and traction control warning lights on
- ABS, VSC, and traction control systems disabled
4. Step-by-Step Diagnosis
Scan for codes and verify C1257 is present
Inspect the wiring and connectors between the Skid Control ECU and the hydraulic actuator for shorts, corrosion, or damage
Test the right rear inlet valve solenoid resistance and check for short to ground
If wiring and solenoid are OK, suspect a faulty Skid Control ECU
5. Frequently Asked Questions
Is it safe to drive?▼
Driving is possible but not recommended because ABS, VSC, and traction control are disabled, increasing the risk of loss of control during hard braking or slippery conditions.
How much does it cost to fix?▼
Repair costs typically range from $200 to $800, depending on whether the issue is a simple wiring repair or requires replacement of the hydraulic actuator or ECU.