AutoCodes – Buick – P16D9 Buick

P16D9 Buick Code - Sensor Supply Voltage Relay Control Circuit High Voltage

Quick Answer

The Reductant Control Module Relay 1 & 2 supply ignition voltage to the Reductant Control Module. Common causes include Faulty Reductant Control Module Relay, Reductant Control Module Relay harness is open or shorted, Reductant Control Module 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: P16D9 Buick indicates Sensor Supply Voltage Relay Control Circuit High Voltage.
Common causes: Common causes include Faulty Reductant Control Module Relay, Reductant Control Module Relay harness is open or shorted, Reductant Control Module 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 307

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 P16D9 Buick Description

The Reductant Control Module Relay 1 & 2 supply ignition voltage to the Reductant Control Module. The Reductant Control Module Relay 2 also supplies ignition voltage to Nitrogen Oxide Sensor 1 & 2 and the Exhaust Particulate Matter Sensor. Both Reductant Control Module Relay 1&2 are controlled by a low side driver in the Engine Control Module (ECM).
The Diagnostic Trouble Code (DTC) will be set when the ECM detects an open circuit, short to voltage or short to ground on the Reductant Control Module Relay control circuit.

OBDII Code P16D9 Buick - Sensor Supply Voltage Relay Control Circuit High Voltage - AutoCodes.com — P16D9 Buick Code - Sensor Supply Voltage Relay Control Circuit High Voltage

What does this mean?

What are the Possible Causes of the DTC P16D9 Buick?

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

How to Fix the DTC P16D9 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 P16D9 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 P16D9 Buick Code

1. What are the common symptoms of OBDII code P16D9 in a Buick related to the Sensor Supply Voltage Relay Control Circuit High Voltage issue?

- Common symptoms include rough engine idling, decreased fuel efficiency, and potential stalling of the vehicle.

2. What are the possible causes of the OBDII code P16D9 in a Buick indicating a high voltage issue in the sensor supply voltage relay control circuit?

- The code may be triggered by a faulty sensor, a malfunctioning relay, damaged wiring, or a problem with the power supply to the sensor.

3. How can I diagnose the Sensor Supply Voltage Relay Control Circuit High Voltage issue causing OBDII code P16D9 in my Buick?

- Diagnosis typically involves inspecting the sensor, checking the relay, testing the wiring for continuity, and verifying the power supply voltage using a multimeter.

4. Is it safe to drive my Buick with the OBDII code P16D9 related to the high voltage problem in the sensor supply voltage relay control circuit?

- It is not recommended to drive the vehicle with this issue as it can lead to further damage to the engine or other components.

5. What are the repair options for fixing the Sensor Supply Voltage Relay Control Circuit High Voltage problem triggering OBDII code P16D9 in a Buick?

- Repair options may include replacing the faulty sensor, repairing or replacing the relay, fixing damaged wiring, or addressing issues with the power supply.

6. Can a DIY enthusiast fix the OBDII code P16D9 in a Buick by themselves, or is it recommended to seek professional help?

- Depending on your skill level and experience with automotive repairs, you may be able to address the issue yourself. However, seeking professional help is recommended for accurate diagnosis and proper repair.

7. How much does it typically cost to repair the Sensor Supply Voltage Relay Control Circuit High Voltage issue leading to OBDII code P16D9 in a Buick?

- The cost of repair can vary depending on the exact cause of the issue, the parts needed, and the labor rates of the repair shop. It's advisable to get quotes from different mechanics for an accurate estimate.

8. Are there any preventive measures I can take to avoid the recurrence of the Sensor Supply Voltage Relay Control Circuit High Voltage issue in my Buick?

- Regular maintenance checks, such as inspecting the sensors and wiring, can help prevent such issues. Ensuring proper voltage levels and addressing any electrical problems promptly can also reduce the likelihood of recurrence.