AutoCodes – GMC – P16BD GMC

P16BD GMC Code - Engine Controls Ignition Relay Feedback Circuit 3 Low Voltage

Quick Answer

There are 4 ignition voltage circuits supplied to the Engine Control Module (ECM). Common causes include Faulty Engine Controls Ignition Relay, Engine Controls Ignition Relay harness is open or shorted, Engine Controls Ignition 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: P16BD GMC indicates Engine Controls Ignition Relay Feedback Circuit 3 Low Voltage.
Common causes: Common causes include Faulty Engine Controls Ignition Relay, Engine Controls Ignition Relay harness is open or shorted, Engine Controls Ignition 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 697

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 Jul 26, 2021

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P16BD GMC Description

There are 4 ignition voltage circuits supplied to the Engine Control Module (ECM). Three are supplied by the Engine Controls Ignition Relay, and the other is supplied by the ignition main relay. The ECM monitors and compares the ignition voltage supplied by the 2 relays. The Diagnostic Trouble Code (DTC) will be set when the ECM detects that the voltage level difference is greater than 3 V between the Engine Controls Ignition Relay feedback circuit 3 and the ignition 1 signal circuit for greater than 1 s.

OBDII Code P16BD GMC - Engine Controls Ignition Relay Feedback Circuit 3 Low Voltage - AutoCodes.com — P16BD GMC Code - Engine Controls Ignition Relay Feedback Circuit 3 Low Voltage

What does this mean?

What are the Possible Causes of the DTC P16BD GMC?

Faulty Engine Controls Ignition Relay
Engine Controls Ignition Relay harness is open or shorted
Engine Controls Ignition Relay circuit poor electrical connection
Faulty Engine Control Module (ECM)

How to Fix the DTC P16BD 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 P16BD 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 P16BD 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 P16BD GMC Code

1. What are common symptoms of OBDII code P16BD GMC?

- Common symptoms include engine misfires, rough idling, stalling, and potential difficulty starting the vehicle.

2. What are the possible causes of OBDII code P16BD GMC?

- The code may be triggered by issues such as a faulty ignition relay, wiring problems in the ignition relay circuit, or a malfunctioning Engine Control Module (ECM).

3. How can I diagnose the cause of OBDII code P16BD GMC?

- Diagnosis typically involves using a scan tool to check for the code, testing the ignition relay, inspecting the wiring for damage, and verifying the ECM's operation.

4. Can a bad battery cause OBDII code P16BD GMC to appear?

- Yes, a weak or failing battery can sometimes cause voltage issues that trigger this code. It's recommended to check the battery's condition as part of the diagnosis.

5. What are some repair tips for addressing OBDII code P16BD GMC?

- Repair may involve replacing the faulty ignition relay, repairing damaged wiring, or reprogramming the ECM if necessary.

6. Is it safe to continue driving with OBDII code P16BD GMC present?

- It's generally not recommended to continue driving with this code active, as it can lead to further engine performance issues and potential breakdowns.

7. Can a DIY enthusiast fix OBDII code P16BD GMC at home?

- Depending on the underlying cause, some DIYers may be able to address this code by replacing the ignition relay or repairing wiring. However, professional diagnosis is recommended for accuracy.

8. How much does it typically cost to repair OBDII code P16BD GMC at a mechanic?

- Repair costs can vary depending on the exact cause of the code and labor rates in your area. Expect to pay for diagnosis time, parts, and labor for the repair.

9. Will resetting the OBDII system clear code P16BD GMC?

- Resetting the system may temporarily clear the code, but if the underlying issue is not addressed, the code is likely to reappear after driving cycles.

10. Is OBDII code P16BD GMC specific to GMC vehicles only?

- While the code is labeled for GMC vehicles, similar issues with ignition relay circuits and low voltage feedback can occur in other makes and models as well.