AutoCodes – GMC – C1203 GMC

C1203 GMC Code - Right Front Wheel Speed Sensor Circuit Open or Shorted

Quick Answer

As the wheel is rotated, the speed sensor produces an AC voltage that increases with wheel speed. Common causes include Faulty Right Front Wheel Speed Sensor, Right Front Wheel Speed Sensor harness is open or shorted, Right Front Wheel Speed Sensor 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: C1203 GMC indicates Right Front Wheel Speed Sensor Circuit Open or Shorted.
Common causes: Common causes include Faulty Right Front Wheel Speed Sensor, Right Front Wheel Speed Sensor harness is open or shorted, Right Front Wheel Speed Sensor 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 210

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 19, 2023

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code C1203 GMC Description

As the wheel is rotated, the speed sensor produces an AC voltage that increases with wheel speed. The Electronic Brake Control Module (EBCM) uses the frequency of the AC signal to calculate the wheel speed. The speed sensor is connected to the EBCM by a twisted pair of wires. Twisting reduces noise susceptibility that may cause a Diagnostic Trouble Code (DTC) to set. The DTC will be set when the EBCM has detected an open, short to ground, or a short to battery on the right front wheel speed circuit.

OBDII Code C1203 GMC - Right Front Wheel Speed Sensor Circuit Open or Shorted - AutoCodes.com — C1203 GMC Code - Right Front Wheel Speed Sensor Circuit Open or Shorted

What does this mean?

What are the Possible Causes of the DTC C1203 GMC?

Faulty Right Front Wheel Speed Sensor
Right Front Wheel Speed Sensor harness is open or shorted
Right Front Wheel Speed Sensor circuit poor electrical connection
Faulty Electronic Brake Control Module (EBCM)

How to Fix the DTC C1203 GMC?

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 C1203 GMC 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.

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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 C1203 GMC Code

1. What does the OBDII code C1203 mean on a GMC?

Code C1203 indicates an issue with the right front wheel speed sensor circuit, such as an open or shorted connection.

2. What are the symptoms of a C1203 code on a GMC?

Common symptoms include an illuminated ABS or traction control warning light, reduced ABS functionality, and possible loss of traction control features.

3. What causes the C1203 code to appear?

Causes include a damaged or faulty right front wheel speed sensor, corroded or damaged wiring, a loose connector, or issues with the ABS control module.

4. Can I still drive my GMC with a C1203 code?

While the vehicle may still be drivable, the ABS and traction control systems may not function properly, increasing the risk of wheel lockup or loss of traction in certain conditions.

5. How do I diagnose a C1203 code on my GMC?

Start by inspecting the right front wheel speed sensor, its wiring, and connectors for visible damage or corrosion. Use a multimeter to test for continuity and proper voltage.

6. How can I fix a C1203 code on a GMC?

Repairs may involve replacing the right front wheel speed sensor, repairing or replacing damaged wiring, or cleaning corroded connectors.

7. How much does it cost to fix a C1203 code on a GMC?

The repair cost varies but typically ranges from $150 to $350, depending on whether the sensor or wiring needs replacement and labor costs.

8. Can a dirty wheel speed sensor cause a C1203 code?

Yes, dirt or debris on the wheel speed sensor can interfere with its signal, potentially triggering the C1203 code.

9. Does clearing the code fix the C1203 issue?

Clearing the code without addressing the underlying problem will only temporarily turn off the warning light, and the code will likely return.

10. How can I prevent a C1203 code from reoccurring?

Regularly inspect the wheel speed sensors and wiring for damage, clean them as needed, and avoid driving in conditions that may expose them to excessive debris or moisture.