P1591 2018 GMC Sierra Code - Body Control Module Engine Speed Request Signal Message Counter Incorrect
Quick Answer
The P1591 diagnostic trouble code (DTC) in a 2018 GMC Sierra indicates that the Body Control Module (BCM) has detected an issue with the engine speed request signal message counter being incorrect. Common causes include Faulty engine speed sensor, Wiring issues or loose connections in the engine speed sensor circuit, BCM software malfunction. 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
- P1591 2018 GMC Sierra indicates Body Control Module Engine Speed Request Signal Message Counter Incorrect.
- Common causes
- Common causes include Faulty engine speed sensor, Wiring issues or loose connections in the engine speed sensor circuit, BCM software malfunction.
- 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 P1591 2018 GMC Sierra Description
The P1591 diagnostic trouble code (DTC) in a 2018 GMC Sierra indicates that the Body Control Module (BCM) has detected an issue with the engine speed request signal message counter being incorrect. The BCM plays a crucial role in controlling various electrical systems in the vehicle, including lighting, door locks, and more. In this case, the BCM is not receiving the correct number of engine speed request signals, which could lead to a variety of issues affecting the vehicle's performance.
Common Causes of P1591 2018 GMC Sierra
- Faulty engine speed sensor
- Wiring issues or loose connections in the engine speed sensor circuit
- BCM software malfunction
- ECM (Engine Control Module) communication issues
- Faulty BCM
Symptoms of P1591 2018 GMC Sierra
- Engine misfires
- Rough idling
- Stalling
- Poor acceleration
- Loss of power
How to Fix P1591 2018 GMC Sierra
- Diagnose the issue by using a scan tool to retrieve the DTC and perform a thorough inspection of the engine speed sensor and related wiring.
- Check for any loose connections or damaged wiring in the engine speed sensor circuit and repair as necessary.
- Update the BCM software to the latest version, if applicable, to address any software-related issues.
- Test the communication between the ECM and BCM to ensure proper operation.
- Replace the engine speed sensor or BCM if they are found to be faulty and causing the incorrect message counter.
Cost to Fix P1591 2018 GMC Sierra
The cost of repairing the P1591 DTC in a 2018 GMC Sierra can vary depending on the specific cause of the issue and the labor rates in your area. On average, the repair costs for this type of issue can range from $200 to $500, including parts and labor. However, it is important to note that diagnosis time and labor rates at auto repair shops can vary significantly, so it is advisable to obtain quotes from multiple shops to get a more accurate estimate. Additionally, rates may be higher at dealerships or in metropolitan areas, while independent shops may offer more competitive pricing.
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Frequently Asked Questions about P1591 2018 GMC Sierra Code
1. What are the common symptoms of OBDII code P1591 in a 2018 GMC Sierra?
- Common symptoms include engine stalling, rough idling, decreased fuel efficiency, and issues with the vehicle's electrical systems.
2. What does the OBDII code P1591 "Body Control Module Engine Speed Request Signal Message Counter Incorrect" mean for a 2018 GMC Sierra?
- This code indicates a communication error between the body control module and the engine control module related to the engine speed request signal counter.
3. What are the possible causes of OBDII code P1591 in a 2018 GMC Sierra?
- Potential causes include faulty wiring or connectors, a malfunctioning body control module, issues with the engine control module, or a software glitch.
4. How can I diagnose the OBDII code P1591 in my 2018 GMC Sierra?
- Diagnosing this code may involve checking the wiring and connectors for any damage, testing the body control module and engine control module, and using a diagnostic scanner to read live data.
5. How serious is the OBDII code P1591 in a 2018 GMC Sierra?
- While the vehicle may still be operable with this code, ignoring it can lead to further electrical or engine performance problems over time.
6. Can I drive my 2018 GMC Sierra with the OBDII code P1591?
- It is generally recommended to address the underlying issue causing the code before driving the vehicle extensively to prevent potential damage or safety hazards.
7. How do I reset the OBDII code P1591 in my 2018 GMC Sierra?
- Clearing the code can be done using an OBDII scanner or by disconnecting the vehicle's battery for a few minutes. However, the code may return if the root problem is not fixed.
8. Can I repair the OBDII code P1591 in my 2018 GMC Sierra myself?
- Depending on your skill level and access to tools, you may be able to address this code yourself by checking and repairing the wiring, connectors, or modules involved.
9. Will the OBDII code P1591 affect my vehicle's emissions test in a 2018 GMC Sierra?
- Yes, unresolved OBDII trouble codes like P1591 can cause a vehicle to fail an emissions test due to the impact on engine performance and emissions control systems.
10. How much does it cost to fix the OBDII code P1591 in a 2018 GMC Sierra?
- The cost of repairs can vary widely depending on the specific cause of the code, ranging from a simple wiring fix to potentially replacing the body control module or engine control module.
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