AutoCodes – GMC – P0699 2018 GMC Sierra

P0699 2018 GMC Sierra Code - 5V Reference 3 Circuit High Voltage

Quick Answer

The Engine Control Module (ECM) has four (4) internal 5 Volt reference circuits (Some models have two (2) internal 5 Volt reference circuits). Common causes include Faulty Sensor on 5 Volt circuit, Sensor on 5 Volt circuit harness is open or shorted, Sensor on 5 Volt 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: P0699 2018 GMC Sierra indicates 5V Reference 3 Circuit High Voltage.
Common causes: Common causes include Faulty Sensor on 5 Volt circuit, Sensor on 5 Volt circuit harness is open or shorted, Sensor on 5 Volt 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.

Save to My Repairs My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

Code Popularity 150

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 17, 2022

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

Code P0699 2018 GMC Sierra Description

The Engine Control Module (ECM) has four (4) internal 5 Volt reference circuits (Some models have two (2) internal 5 Volt reference circuits). Each internal reference circuit provides external 5 Volt reference circuits for more than one sensor. A short to ground or short to voltage on one external 5 Volt reference circuit can affect all the components connected to the same internal 5 Volt reference circuit. The Diagnostic Trouble Code (DTC) will be set when the ECM detects a higher than the expected voltage on any of the 5 Volt reference circuits for greater than 0.5 s.

OBDII Code P0699 2018 GMC Sierra - 5V Reference 3 Circuit High Voltage - AutoCodes.com — P0699 2018 GMC Sierra Code - 5V Reference 3 Circuit High Voltage

What does this mean?

What are the Possible Causes of the DTC P0699 2018 GMC Sierra?

Faulty Sensor on 5 Volt circuit
Sensor on 5 Volt circuit harness is open or shorted
Sensor on 5 Volt circuit poor electrical connection
Faulty Engine Control Module (ECM)

How to Fix the DTC P0699 2018 GMC Sierra?

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 does this mean?

Code Tech Notes

Disconnecting one component at a time from the affected 5 Volt reference circuit while observing the scan tool 5 Volt Reference Circuit Status parameter may help locate the fault. The scan tool parameter will change from Malfunction to OK when the source of the fault is disconnected. If all 5 Volt reference components have been disconnected and a fault is still indicated, the fault may exist in the wiring harness.

The 5 Volt reference 3 circuit provides 5 Volt to the following sensors: (Some models may have different sensors, please consult the factory service manual for the list of sensors for your model and year)

- Accelerator pedal position sensor 2
- Manifold absolute pressure sensor

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0699 2018 GMC Sierra 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 P0699 2018 GMC Sierra code?

Need more information on how to fix the P0699 2018 GMC Sierra code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0699 2018 GMC Sierra code diagnosed by a professional: Find a repair shop in your area

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 P0699 2018 GMC Sierra Code

1. What does the OBDII code P0699 mean on a 2018 GMC Sierra?

P0699 indicates a high voltage issue in the 5V Reference 3 Circuit, which provides power to certain engine sensors.

2. What are the common symptoms of a P0699 code in a GMC Sierra?

Symptoms may include a check engine light, erratic engine performance, poor fuel efficiency, or sensor-related issues.

3. What causes the P0699 code to appear on a 2018 GMC Sierra?

Common causes include a short to voltage in the wiring, a faulty sensor using the 5V reference circuit, or a defective Engine Control Module (ECM).

4. Can a P0699 code cause drivability issues?

Yes, this code can cause drivability problems such as rough idle, stalling, or inconsistent throttle response due to disrupted sensor operation.

5. How can I diagnose a P0699 code on my GMC Sierra?

Start by inspecting the 5V reference circuit wiring for damage, test the sensors connected to the circuit, and check the ECM for proper operation.

6. Which sensors use the 5V Reference 3 Circuit on a 2018 GMC Sierra?

Common sensors include the manifold absolute pressure (MAP) sensor, throttle position sensor (TPS), and other engine management sensors.

7. Is it safe to drive with a P0699 code on my GMC Sierra?

Driving may be possible but is not recommended, as the code indicates a problem that can lead to further engine performance issues or damage.

8. How do I fix a P0699 code on a 2018 GMC Sierra?

Repairs may include replacing damaged wiring, fixing shorts or open circuits, replacing faulty sensors, or reprogramming or replacing the ECM if necessary.

9. Can a blown fuse cause the P0699 code to appear?

Yes, a blown fuse in the 5V reference circuit can disrupt power delivery and trigger the code.

10. How much does it typically cost to repair a P0699 code issue?

The repair cost varies depending on the issue but can range from $50 for simple wiring repairs to $500 or more if the ECM or multiple sensors need replacement.