Engine-Codes.com
Engine-Codes – Generic – P138A

P138A Code - Glow Plug Control Module Control Circuit Range/Performance

Quick Answer

The diagnostic trouble code P138A indicates a problem with the Glow Plug Control Module Control Circuit Range/Performance in a vehicle. Common causes include Faulty glow plug control module, Wiring issues or loose connections in the control circuit, Malfunctioning glow plugs. 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
P138A indicates Glow Plug Control Module Control Circuit Range/Performance.
Common causes
Common causes include Faulty glow plug control module, Wiring issues or loose connections in the control circuit, Malfunctioning glow plugs.
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.
What is this?
Table of contents Created and updated by William Orellana on Sep 08, 2024
💬 Need more help? Ask Auto Expert for instant answers — it's free!
AutoCodes App

Fix Your Car Smarter

Try the New AutoCodes App!

Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.

AutoCodes App on Google Play

Code P138A Description

The diagnostic trouble code P138A indicates a problem with the Glow Plug Control Module Control Circuit Range/Performance in a vehicle. The glow plug control module is responsible for monitoring and controlling the glow plugs in a diesel engine. Glow plugs are essential for starting a diesel engine, especially in cold weather conditions, as they heat up the air in the combustion chamber to facilitate ignition.

OBDII Code P138A - Glow Plug Control Module Control Circuit Range/Performance
P138A Code - Glow Plug Control Module Control Circuit Range/Performance

Common Causes of P138A

  1. Faulty glow plug control module
  2. Wiring issues or loose connections in the control circuit
  3. Malfunctioning glow plugs
  4. Corrosion or damage to the connectors
  5. Software or programming issues with the control module

Symptoms of P138A

  1. Difficulty starting the engine, especially in cold weather conditions
  2. Rough idling or stalling
  3. Decreased fuel efficiency
  4. Engine misfires
  5. Illumination of the check engine light

How to Fix P138A

  1. Diagnose the issue using a diagnostic scanner to confirm the code and pinpoint the exact cause of the problem.
  2. Inspect the wiring and connections in the glow plug control circuit for any damage or loose connections.
  3. Test the glow plugs to ensure they are functioning properly and replace any faulty ones.
  4. Replace the glow plug control module if it is determined to be the source of the problem.
  5. Clear the fault code from the vehicle's computer system and test the vehicle to ensure the issue has been resolved.

Cost to Fix P138A

The cost of repairing a glow plug control module control circuit range/performance issue can vary depending on the specific cause of the problem and the make and model of the vehicle. On average, the parts for this repair can range from $200 to $500, while labor costs can range from $100 to $300. Overall, the total repair cost can be anywhere from $300 to $800. It's important to note that these are rough estimates, and actual costs may vary based on individual circumstances and location. It's recommended to consult with a professional mechanic to get an accurate quote for the repair.

Need more information about the P138A code?

Need more information on how to fix the P138A code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P138A code diagnosed by a professional: Find a repair shop in your area

Code P138A Information for Specific Makes

  • P138A Ford — Glow Plug Control Module Control Circuit Range/Performance
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 P138A Code

1. What are the common symptoms of OBDII code P138A (Glow Plug Control Module Control Circuit Range/Performance)?

- Common symptoms include hard starting, rough idling, decreased engine performance, and illuminated Check Engine Light.

2. What are the possible causes of OBDII code P138A?

- The code P138A can be triggered by issues such as a faulty glow plug control module, damaged wiring or connectors, or a malfunctioning glow plug relay.

3. How can I diagnose OBDII code P138A?

- Diagnosing code P138A typically involves using a scan tool to read the code, checking the glow plug control module and related components for visible damage, and testing the circuitry for proper functioning.

4. Can a faulty glow plug cause OBDII code P138A to appear?

- Yes, a faulty glow plug can contribute to triggering code P138A if it affects the control module's ability to regulate the glow plug system.

5. What is the recommended repair approach for OBDII code P138A?

- The recommended repair approach involves inspecting and repairing any damaged wiring or connectors, replacing the glow plug control module if necessary, and addressing any underlying glow plug issues.

6. Are there any specific tips for preventing OBDII code P138A from reoccurring?

- Regularly checking the glow plug system, ensuring proper maintenance of the glow plug control module, and addressing any issues promptly can help prevent code P138A from reoccurring.

7. Can driving with OBDII code P138A cause further damage to the vehicle?

- Continuing to drive with code P138A can potentially lead to reduced engine performance, increased fuel consumption, and possible damage to other engine components over time.

8. Is it safe to drive with the Check Engine Light illuminated due to code P138A?

- While driving with the Check Engine Light on may be possible, it is recommended to address the underlying issue causing code P138A to prevent any potential long-term damage to the vehicle.

9. Can a DIY enthusiast repair OBDII code P138A at home?

- Depending on the level of expertise and access to tools, a DIY enthusiast may be able to address certain aspects of the repair for code P138A, such as inspecting wiring and connectors.

10. How much does it typically cost to repair OBDII code P138A at a professional auto repair shop?

- The cost of repairing code P138A at a professional auto repair shop can vary depending on the extent of the issue, parts needed, and labor costs, but it may range from $200 to $500 on average.

Discuss the causes and fixes for P138A OBDII Code

Submit a New Comment

Code P138A comments

No comments found for this page.