Suspension Height Sensor Supply Overvoltage
The C1722 code indicates that the air suspension control module (VDCM or equivalent) has detected an abnormally high voltage on the power supply circuit for the air suspension height sensor, exceeding the calibrated threshold. This supply circuit provides reference voltage (typically 5V or 12V depending on manufacturer design) to the height sensors. A short to battery positive (B+) in this circuit prevents accurate suspension position readings and can damage the sensors. The control module continuously monitors the supply voltage to detect this fault.
1. Commonly Affected Makes
2. Most Common Causes
- Short to battery positive (B+) in the height sensor power supply wiring
- Internally shorted air suspension height sensor
- Contaminated or damaged height sensor connector causing a short between power pins and B+
- Faulty air suspension control module with internal power supply circuit failure
- Defective splice or electrical joint in the harness contacting a B+ circuit
3. Symptoms You Will Notice
- Suspension warning light illuminated on the dashboard
- Abnormal ride height or suspension not leveling properly
- Air suspension system inoperative or stuck in one position
- Possible blown fuse for the height sensor circuit
4. Step-by-Step Diagnosis
Scan for additional codes and verify C1722 is present
Visually inspect the height sensor wiring and connector for damage, corrosion, or shorts to B+
Measure voltage at the height sensor power supply pin; should be 5V or 12V as specified; if higher, locate the short
Disconnect the height sensor and check if voltage drops to normal; if so, replace the sensor
Check for shorts between the power supply wire and B+ circuits using a multimeter
If wiring and sensor are okay, test the control module output or replace the module
5. Frequently Asked Questions
Is it safe to drive?▼
Driving with this code is not recommended as the suspension may not function correctly, leading to poor handling, uneven ride height, and potential damage to the air suspension components. Have the vehicle inspected promptly.
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 a height sensor or control module can run $400-$800 or more.