AutoCodes – Generic – U3004

U3004 Code - Accessory Power Relay

Quick Answer

The Power Steering Control Module (PSCM) monitors various inputs and outputs of the Electric Power-Assisted Steering (EPAS) system in order to keep the system operating at peak capacity. Common causes include Faulty Accessory Power Relay, Accessory Power Relay harness is open or shorted, Accessory Power Relay 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: U3004 indicates Accessory Power Relay.
Common causes: Common causes include Faulty Accessory Power Relay, Accessory Power Relay harness is open or shorted, Accessory Power Relay 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 6,757

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 Jun 18, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U3004 Description

The Power Steering Control Module (PSCM) monitors various inputs and outputs of the Electric Power-Assisted Steering (EPAS) system in order to keep the system operating at peak capacity. Information provided by sensors (steering torque, vehicle speed, vehicle travel distance, etc.) are all compared to programmed and learned information. Likewise, outputs like the motor and steering rack (travel) are tested against programmed and learned information. This test generates a RVC for a new PSCM when directed to do so from pinpoint test. A RVC is required to order a new PSCM and to document billing for payment.

OBDII Code U3004 - Accessory Power Relay - AutoCodes.com — U3004 Code - Accessory Power Relay

What does this mean?

What are the Possible Causes of the DTC U3004?

Faulty Accessory Power Relay
Accessory Power Relay harness is open or shorted
Accessory Power Relay circuit poor electrical connection

How to Fix the DTC U3004?

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 U3004 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 U3004 code?

Need more information on how to fix the U3004 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the U3004 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

U3004 Ford — Accessory Power Relay
U3004 Lincoln — Accessory Power Relay
U3004 Mercury — Accessory Power Relay

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 U3004 Code

1. What are the common symptoms of an OBDII code U3004 related to the Accessory Power Relay?

- Common symptoms include issues with power windows, door locks, interior lights, and other accessories not functioning properly.

2. What is the typical cause of an OBDII code U3004 related to the Accessory Power Relay?

- The most common cause is a malfunctioning accessory power relay, which can lead to a loss of power to various components in the vehicle.

3. How can I diagnose if the Accessory Power Relay is causing an OBDII code U3004?

- You can use a multimeter to test the relay for continuity and proper voltage, or consult a professional mechanic for a thorough diagnosis.

4. Can a faulty Accessory Power Relay affect the overall performance of the vehicle?

- Yes, a faulty relay can impact the overall performance by causing electrical components to malfunction, affecting convenience features and potentially draining the battery.

5. What are some repair tips for fixing an OBDII code U3004 related to the Accessory Power Relay?

- Repair tips may include checking and replacing the relay, inspecting wiring connections, and ensuring proper power supply to the affected components.

6. Are there any safety concerns associated with an Accessory Power Relay issue?

- While an Accessory Power Relay issue is more of an inconvenience, it can affect safety if critical components like power windows or door locks fail to work in emergency situations.

7. Can resetting the OBDII system clear an U3004 code related to the Accessory Power Relay?

- Resetting the OBDII system may temporarily clear the code, but if the underlying issue with the relay is not addressed, the code is likely to reappear.

8. Is it possible to drive the vehicle with an unresolved OBDII code U3004 linked to the Accessory Power Relay?

- It is generally not recommended to drive the vehicle with unresolved electrical issues, as they can lead to further problems and potential safety hazards.

9. How much does it typically cost to repair an OBDII code U3004 associated with the Accessory Power Relay?

- The cost of repair can vary depending on the extent of the issue, but it may involve replacing the relay, which can range from a relatively inexpensive part to a moderate repair cost.

10. Can a DIY enthusiast replace the Accessory Power Relay to fix an OBDII code U3004 issue?

- Yes, if you have the necessary tools and knowledge, replacing the Accessory Power Relay can be a DIY project. However, if you are unsure, it's best to consult a professional mechanic for assistance.