OBD2 Code C1150: Two-Speed Axle Switch Short
The C1150 code indicates that the vehicle's control module has detected a short circuit to battery voltage (Vbatt) in the two-speed rear axle input switch circuit. This system allows the driver to select between a direct or reduced axle ratio to optimize performance or load capacity. The short to Vbatt means the signal circuit is continuously receiving battery voltage, preventing the module from correctly determining the switch position or rear axle state.
1. Commonly Affected Makes
2. Most Common Causes
- Faulty or internally damaged two-speed rear axle switch
- Wiring harness insulation deterioration causing contact with a voltage source
- Switch connector with bent pins, corrosion, or moisture leading to a short circuit
- Incorrect modification to the vehicle's wiring harness
- Internal failure of the control module that monitors the circuit
3. Symptoms You Will Notice
- Check Engine Light or Service 4WD light illuminated
- Inability to shift between two-speed axle ratios
- Axle stuck in one ratio (direct or reduced)
- Reduced fuel economy or performance
4. Step-by-Step Diagnosis
Scan for additional codes and verify C1150 is present
Visually inspect the two-speed axle switch and its connector for damage, corrosion, or bent pins
Check the wiring harness for chafing, exposed wires, or contact with battery voltage sources
Test the switch circuit for continuity and shorts to battery voltage using a multimeter
If wiring and switch are okay, suspect a faulty control module and perform further diagnostics
5. Frequently Asked Questions
Is it safe to drive?▼
Driving with code C1150 is generally safe in the short term, but the two-speed axle may not shift properly, potentially affecting performance or fuel economy. Have it diagnosed soon to avoid further issues.
How much does it cost to fix?▼
Repair costs typically range from $100 to $400, depending on whether the switch, wiring, or control module needs replacement. Diagnostic fees are usually around $100.