ABS Rear Inlet Valve Circuit Short to Battery
The C1208 code indicates a short to battery positive voltage in the rear ABS inlet valve solenoid circuit. This valve controls brake fluid flow to the rear brakes during ABS activation. The ABS module detected abnormally high voltage on the valve coil circuit when it should be off, typically caused by a short to battery positive in the wiring or the solenoid coil itself.
1. Commonly Affected Makes
2. Most Common Causes
- Wiring harness short to battery positive in the rear ABS inlet valve circuit
- Internal short to battery in the rear ABS inlet valve solenoid coil
- Damaged, corroded, or moisture-contaminated ABS module connector or terminals
- Internal failure of the ABS control module (valve driver circuit)
- Wiring harness chafed or heat-damaged near the ABS unit
3. Symptoms You Will Notice
- ABS warning light illuminated on the dashboard
- ABS system may be disabled or function intermittently
4. Step-by-Step Diagnosis
Scan for additional ABS codes and record freeze frame data
Visually inspect the ABS module connector and wiring for damage, corrosion, or chafing
Measure voltage at the rear inlet valve solenoid circuit with the ignition on and engine off; compare to specifications
Check for continuity to ground and battery positive on the valve circuit to isolate the short
If wiring and connector are okay, test the valve solenoid resistance; replace valve if out of spec
If all else passes, suspect internal ABS module failure and consider replacement or reprogramming
5. Frequently Asked Questions
Is it safe to drive?▼
No, it is not safe to drive. The ABS system may be disabled, increasing the risk of wheel lockup during hard braking, especially on slippery surfaces. Have the vehicle diagnosed and repaired immediately.
How much does it cost to fix?▼
Repair costs typically range from $200 to $800, depending on the cause. A simple wiring repair may cost $200–$400, while replacing an ABS module can run $500–$800 or more.