AutoCodes – Buick – P16AF Buick

P16AF Buick Code - Engine Controls Ignition Relay Feedback Circuit 2 Low Voltage

Quick Answer

There are 3 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: P16AF Buick indicates Engine Controls Ignition Relay Feedback Circuit 2 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 394

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 Aug 13, 2022

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P16AF Buick Description

There are 3 ignition voltage circuits supplied to the Engine Control Module (ECM). Two 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 the engine controls ignition relay feedback circuit 2 is less than 5 V.

OBDII Code P16AF Buick - Engine Controls Ignition Relay Feedback Circuit 2 Low Voltage - AutoCodes.com — P16AF Buick Code - Engine Controls Ignition Relay Feedback Circuit 2 Low Voltage

What does this mean?

What are the Possible Causes of the DTC P16AF Buick?

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 P16AF Buick?

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 P16AF Buick 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.

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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 P16AF Buick Code

What does the OBDII code P16AF mean for a Buick?

P16AF indicates an issue with the Ignition Relay Feedback Circuit 2, specifically low voltage detected by the engine control module (ECM).

What are the common symptoms of P16AF?

Symptoms may include difficulty starting the engine, intermittent stalling, reduced engine performance, or the check engine light being illuminated.

What causes the P16AF code?

Possible causes include a faulty ignition relay, damaged wiring or connectors in the feedback circuit, or a malfunctioning ECM.

Can a bad battery cause the P16AF code?

Yes, a weak or failing battery can lead to low voltage issues, potentially triggering the P16AF code.

How can I diagnose the P16AF code on my Buick?

Start by inspecting the ignition relay, wiring, and connectors for damage or corrosion. Use a multimeter to check for proper voltage and continuity in the feedback circuit.

Can I drive my Buick with the P16AF code?

Driving with this code may lead to further damage or unreliable engine performance. It's best to address the issue promptly.

How do I fix the P16AF code?

Repairs may include replacing the ignition relay, fixing damaged wiring or connectors, clearing corrosion, or reprogramming or replacing the ECM if necessary.

Will clearing the code fix the P16AF problem?

Clearing the code may temporarily remove the check engine light, but the underlying issue must be addressed to prevent the code from returning.

How much does it cost to fix the P16AF code?

Repair costs vary depending on the cause, but typical expenses may range from $50 to $200 for ignition relay or wiring repairs, and higher if ECM replacement is needed.

How do I prevent the P16AF code from recurring?

Regular maintenance, such as battery checks, ensuring clean and secure electrical connections, and timely replacement of worn components, can help prevent this issue.