AutoCodes – Generic – C1751

C1751 Code - Continuous Electric Current To Height Control Compressor

Quick Answer

If the vehicle height control is attempted on a steeply sloping road, when the vehicle is overloaded, or when the vehicle is jacked up with the engine running, the compressor motor operates continuously to raise vehicle height, and causes electric current to flow to the AIR SUS relay for 100 seconds or longer. Common causes include Faulty Height Control Compressor, Height Control Compressor harness is open or shorted, Height Control Compressor circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: C1751 indicates Continuous Electric Current To Height Control Compressor.
Common causes: Common causes include Faulty Height Control Compressor, Height Control Compressor harness is open or shorted, Height Control Compressor circuit poor electrical connection.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 14,953

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Nov 22, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code C1751 Description

If the vehicle height control is attempted on a steeply sloping road, when the vehicle is overloaded, or when the vehicle is jacked up with the engine running, the compressor motor operates continuously to raise vehicle height, and causes electric current to flow to the AIR SUS relay for 100 seconds or longer. Thus DTC C1751/51 may be output and vehicle height control may be suspended. (This is not electrically abnormal.) In this case, however, the vehicle height operation is resumed approx. 10 min. after the ignition switch is turned ON after the ECU detects the first error. If ECU detects another error, it takes 70 minutes until control is resumed.

OBDII Code C1751 - Continuous Electric Current To Height Control Compressor - AutoCodes.com — C1751 Code - Continuous Electric Current To Height Control Compressor

What does this mean?

What are the Possible Causes of the DTC C1751?

Faulty Height Control Compressor
Height Control Compressor harness is open or shorted
Height Control Compressor circuit poor electrical connection

How to Fix the DTC C1751?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the C1751 code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

Need more information about the C1751 code?

Need more information on how to fix the C1751 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the C1751 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

C1751 Lexus — Continuous Electric Current To Height Control Compressor
C1751 Toyota — Continuous Electric Current To Height Control Compressor

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about C1751 Code

1. What are the common symptoms of OBDII code C1751?

The common symptoms of OBDII code C1751 include a noticeable change in the vehicle's ride height, uneven suspension, and potential issues with the height control system.

2. What can cause OBDII code C1751 to trigger?

OBDII code C1751, Continuous Electric Current To Height Control Compressor, can be triggered by a malfunction in the height control compressor, faulty height sensors, wiring issues, or a problem with the height control module.

3. How can I diagnose the cause of OBDII code C1751?

Diagnosing OBDII code C1751 involves checking the height control compressor, inspecting the height sensors, examining the wiring for any damage, and testing the height control module for proper functionality.

4. Is it safe to drive with OBDII code C1751 active?

It is not recommended to drive with OBDII code C1751 active, as it can lead to potential safety issues due to compromised suspension and ride height control.

5. Can OBDII code C1751 be reset without fixing the underlying issue?

Resetting OBDII code C1751 without fixing the underlying issue will only temporarily clear the code. The issue causing the code will persist until properly diagnosed and repaired.

6. What are some repair tips for fixing OBDII code C1751?

Repair tips for OBDII code C1751 include checking and repairing any damaged wiring, replacing faulty height sensors, testing and potentially replacing the height control compressor, and ensuring proper functionality of the height control module.

7. How much does it typically cost to repair OBDII code C1751?

The cost of repairing OBDII code C1751 can vary depending on the specific cause of the issue, parts needed for replacement, and labor costs. It is recommended to consult with a professional mechanic for an accurate estimate.

8. Can I fix OBDII code C1751 myself, or should I seek professional help?

While some DIY enthusiasts may be able to diagnose and repair OBDII code C1751 themselves, it is generally recommended to seek professional help for proper diagnosis and repair to ensure the issue is resolved correctly.

9. Are there any preventive measures to avoid OBDII code C1751 in the future?

To prevent OBDII code C1751 in the future, regular maintenance of the height control system, checking for any signs of wear or damage, and addressing any suspension issues promptly can help avoid triggering the code.

10. Will OBDII code C1751 cause the vehicle to fail an emissions test?

OBDII code C1751 is related to the height control compressor and suspension system, so it should not cause the vehicle to fail an emissions test. However, it is still recommended to address and repair the issue promptly for optimal vehicle performance.