AutoCodes – GMC – P1008 2017 GMC Sierra

P1008 2017 GMC Sierra Code - Engine Coolant Bypass Valve Command Signal Message Counter Incorrect

Quick Answer

Control modules connected to the serial data circuits monitor the communication during normal vehicle operation. Common causes include Faulty Engine Coolant Bypass Valve, Engine Coolant Bypass Valve harness is open or shorted, Engine Coolant Bypass Valve 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: P1008 2017 GMC Sierra indicates Engine Coolant Bypass Valve Command Signal Message Counter Incorrect.
Common causes: Common causes include Faulty Engine Coolant Bypass Valve, Engine Coolant Bypass Valve harness is open or shorted, Engine Coolant Bypass Valve 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 163

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 18, 2022

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P1008 2017 GMC Sierra Description

Control modules connected to the serial data circuits monitor the communication during normal vehicle operation. Operating information and commands are exchanged among the control modules. Each module on the serial data circuit maintains a transmit error counter and a receive error counter. The counter values increase with detected errors and decrease with error-free messages. The Diagnostic Trouble Code (DTC) will be set when the Engine Coolant Bypass Valve Command Signal Message Counter is Incorrect.

OBDII Code P1008 2017 GMC Sierra - Engine Coolant Bypass Valve Command Signal Message Counter Incorrect - AutoCodes.com — P1008 2017 GMC Sierra Code - Engine Coolant Bypass Valve Command Signal Message Counter Incorrect

What does this mean?

What are the Possible Causes of the DTC P1008 2017 GMC Sierra?

Faulty Engine Coolant Bypass Valve
Engine Coolant Bypass Valve harness is open or shorted
Engine Coolant Bypass Valve circuit poor electrical connection

How to Fix the DTC P1008 2017 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 is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P1008 2017 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 P1008 2017 GMC Sierra 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 P1008 2017 GMC Sierra Code

1. What does the OBDII code P1008 mean on a 2017 GMC Sierra?

P1008 indicates an issue with the engine coolant bypass valve command signal, where the message counter is deemed incorrect by the vehicle's computer.

2. What are the symptoms of code P1008 in a 2017 GMC Sierra?

Common symptoms include engine overheating, irregular coolant flow, reduced heating or cooling performance, and possibly an illuminated check engine light.

3. What causes the P1008 code on a GMC Sierra?

The code can result from a faulty engine coolant bypass valve, damaged wiring or connectors, a malfunctioning powertrain control module (PCM), or software issues.

4. Can I drive my 2017 GMC Sierra with a P1008 code?

Driving with this code may be possible but is not recommended, as it could lead to overheating and potential engine damage if coolant flow is not properly regulated.

5. How do you diagnose the P1008 code on a GMC Sierra?

Diagnosis typically involves inspecting the coolant bypass valve, checking for damaged wiring or connectors, confirming proper signal communication, and testing the PCM functionality.

6. How can the P1008 code be fixed on a 2017 GMC Sierra?

Repairs may include replacing the coolant bypass valve, repairing damaged wiring or connectors, updating PCM software, or replacing the PCM if necessary.

7. What tools are needed to fix the P1008 code?

You may need an OBDII scanner, a multimeter to test electrical components, and potentially specialty tools to access and replace the coolant bypass valve.

8. How much does it cost to repair a P1008 code on a GMC Sierra?

The cost varies, but replacing the coolant bypass valve typically ranges from $150 to $300, including parts and labor. Additional wiring or PCM repairs may increase costs.

9. Could a low coolant level cause the P1008 code?

While low coolant levels can cause overheating issues, they are unlikely to trigger the P1008 code specifically. However, itâ€™s still important to maintain correct coolant levels.

10. Does a P1008 code always require a part replacement?

Not always. Sometimes, the issue can be resolved by repairing damaged wiring, cleaning electrical connections, or reprogramming the PCM.