AutoCodes – Generic – P138A

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

Quick Answer

The Engine Control Module (ECM) monitors the Glow Plug Control Module. Common causes include Faulty Glow Plug Control Module, Glow Plug Control Module harness is open or shorted, Glow Plug Control Module 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: P138A indicates Glow Plug Control Module Control Circuit Range/Performance.
Common causes: Common causes include Faulty Glow Plug Control Module, Glow Plug Control Module harness is open or shorted, Glow Plug Control Module 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 3,264

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 Sep 24, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P138A Description

The Engine Control Module (ECM) monitors the Glow Plug Control Module. The ECM sets the OBDII code when Glow Plug Control Module is not working properly.

OBDII Code P138A - Glow Plug Control Module Control Circuit Range/Performance - AutoCodes.com — P138A Code - Glow Plug Control Module Control Circuit Range/Performance

What does this mean?

What are the Possible Causes of the DTC P138A?

Faulty Glow Plug Control Module
Glow Plug Control Module harness is open or shorted
Glow Plug Control Module circuit poor electrical connection

How to Fix the DTC P138A?

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 P138A 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 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

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.