C1740: Right Front Height Sensor Circuit
Diagnostic trouble code C1740 indicates a fault in the right front ride height sensor circuit, which is part of the vehicle's air suspension or auto-leveling system. This sensor measures the suspension height at the right front wheel and sends the signal to the suspension control module (VSM/RSM). The fault can be caused by an open circuit, short to ground or battery voltage in the sensor wiring, or a defective sensor. As a result, the system cannot determine the correct ride height for that corner, affecting leveling compensation and ride quality.
1. Commonly Affected Makes
2. Most Common Causes
- Damaged or disconnected right front suspension height sensor
- Open circuit, short to ground, or short to voltage in the sensor wiring
- Corroded, oxidized, or damaged pins in the sensor connector
- Internal failure of the suspension control module (VSM/RSM)
- Mechanical issue with the sensor link or arm (disconnected or physically damaged)
3. Symptoms You Will Notice
- Uneven ride height, especially at the right front corner
- Illuminated suspension warning light or check engine light
- Poor ride quality or harshness
- Vehicle may not level properly when loaded
4. Step-by-Step Diagnosis
Scan for additional codes and check freeze frame data
Visually inspect the right front height sensor, connector, and linkage for damage or corrosion
Test the sensor circuit for continuity, shorts, and proper voltage reference
If wiring is okay, test the sensor output signal while manually moving the suspension
If sensor and wiring are good, suspect a faulty suspension control module
5. Frequently Asked Questions
Is it safe to drive?▼
Yes, but with caution. The vehicle may have reduced ride quality and improper leveling, but it is generally safe for short trips. Have it diagnosed soon to avoid further suspension component wear.
How much does it cost to fix?▼
Repair costs typically range from $200 to $600, depending on whether the sensor, wiring, or module needs replacement. Sensor replacement is usually $150-$350, while module replacement can exceed $500.