AutoCodes – GMC – P1F5B GMC

P1F5B GMC Code - 14 Volt Power Module Status Terminal Circuit High Voltage

Quick Answer

The ECM uses two circuits to control and monitor the state of the 14V power module, often referred to as the accessory DC power control module. Common causes include Faulty 14 Volt Power Module, 14 Volt Power Module harness is open or shorted, 14 Volt Power 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: P1F5B GMC indicates 14 Volt Power Module Status Terminal Circuit High Voltage.
Common causes: Common causes include Faulty 14 Volt Power Module, 14 Volt Power Module harness is open or shorted, 14 Volt Power 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 773

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 Apr 26, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P1F5B GMC Description

The ECM uses two circuits to control and monitor the state of the 14V power module, often referred to as the accessory DC power control module.
The status circuit functions much like the F Terminal circuit on a generator equipped vehicle. A high side driver in the 14V power module applies a duty cycled voltage to the ECM. The duty cycle indicates 14V power module internal temperature and operational condition. The ECM will detect faults on the 14V power module status circuit when the vehicle is ON.

OBDII Code P1F5B GMC - 14 Volt Power Module Status Terminal Circuit High Voltage - AutoCodes.com — P1F5B GMC Code - 14 Volt Power Module Status Terminal Circuit High Voltage

What does this mean?

What are the Possible Causes of the DTC P1F5B GMC?

Faulty 14 Volt Power Module
14 Volt Power Module harness is open or shorted
14 Volt Power Module circuit poor electrical connection

How to Fix the DTC P1F5B 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 P1F5B 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.

Need more information about the P1F5B GMC code?

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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 P1F5B GMC Code

What does the OBD-II code P1F5B mean on a GMC vehicle?

The P1F5B code indicates an issue with the 14 Volt Power Module Status Terminal Circuit, specifically detecting a high voltage condition.

What are the common symptoms of the P1F5B code?

Symptoms may include an illuminated check engine light, electrical system malfunctions, reduced charging system performance, or intermittent power loss.

What causes the P1F5B code to appear?

Possible causes include a faulty 14 Volt Power Module, damaged or corroded wiring, poor electrical connections, or a malfunctioning control module.

Can I continue driving with the P1F5B code active?

Itâ€™s possible to drive for a short time, but prolonged operation could cause further electrical issues or leave the battery undercharged, leading to a breakdown.

How is the P1F5B code diagnosed?

A technician will use a scan tool to confirm the code, inspect the wiring and connectors for damage, and test the 14 Volt Power Module and related circuits.

How can I fix the P1F5B code on my GMC?

Repairs may involve replacing the 14 Volt Power Module, repairing damaged wiring, cleaning connections, or reprogramming the control module if needed.

What tools are required to diagnose the P1F5B code?

Tools may include an OBD-II scanner, a digital multimeter, and wiring diagrams to trace and test the affected circuits.

Is the P1F5B code related to the battery or alternator?

While not directly related, issues with the 14 Volt Power Module can affect battery charging and alternator operation, so these components may need inspection.

Can a weak battery trigger the P1F5B code?

A weak or failing battery is not a direct cause of this code but could exacerbate electrical issues and should be tested as part of the diagnostic process.

How much does it cost to repair the P1F5B code?

Repair costs vary but may range from $150 to $500 or more, depending on whether the issue is with wiring, the 14 Volt Power Module, or the control module.