P0657 GMC Code - Actuator High Control Circuit Group 1
Quick Answer
The Transmission Control Module (TCM) receives information from a variety of sensors, switches, and serial data information from other control modules. Common causes include Faulty Transmission Control Solenoid Valve, Faulty Transmission Control Module (TCM), Transmission Control Module harness is open or shorted. 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
- P0657 GMC indicates Actuator High Control Circuit Group 1.
- Common causes
- Common causes include Faulty Transmission Control Solenoid Valve, Faulty Transmission Control Module (TCM), Transmission Control Module harness is open or shorted.
- 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.
Code P0657 GMC Description
What are the Possible Causes of the DTC P0657 GMC?
- Faulty Transmission Control Solenoid Valve
- Faulty Transmission Control Module (TCM)
- Transmission Control Module harness is open or shorted
- Transmission Control Module circuit poor electrical connection
How to Fix the DTC P0657 GMC?
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 P0657 GMC 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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Information for Specific GMC Models
- P0657 2014 GMC Sierra — Actuator High Control Circuit Group 1
- P0657 2015 GMC Sierra — Actuator High Control Circuit Group 1
- P0657 2016 GMC Sierra — Actuator High Control Circuit Group 1
- P0657 2017 GMC Sierra — Actuator High Control Circuit Group 1
- P0657 2018 GMC Sierra — Actuator High Control Circuit Group 1
Frequently Asked Questions about P0657 GMC Code
What does the OBDII code P0657 mean for a GMC vehicle?
P0657 indicates an issue with the Actuator High Control Circuit Group 1, meaning the PCM has detected an electrical fault in the control circuit for one or more actuators.
What are the common symptoms of code P0657 in GMC vehicles?
Symptoms may include poor engine performance, transmission shifting issues, warning lights on the dashboard, or the vehicle entering limp mode.
What causes the P0657 code to appear on a GMC?
Potential causes include damaged wiring, faulty connectors, a short or open circuit, a malfunctioning actuator, or a failing PCM.
Can a faulty PCM cause the P0657 code?
Yes, a failing PCM can sometimes lead to the P0657 code, although this is less common compared to wiring or actuator issues.
How can I diagnose the P0657 code on my GMC?
Start by inspecting wiring and connectors for damage or corrosion, then test the actuator circuits using a multimeter. If no issues are found, check the PCM for faults.
Is it safe to drive a GMC with the P0657 code?
Driving with this code is not recommended, as it may cause drivability issues, reduced performance, or further damage to the vehicle.
How do I repair a GMC with a P0657 code?
Repairs may include replacing damaged wiring, repairing faulty connectors, replacing the affected actuator, or reprogramming or replacing the PCM.
What tools are needed to fix the P0657 code on a GMC?
You’ll need an OBDII scanner, a multimeter, and basic hand tools to inspect and repair wiring, connectors, and actuators.
Can a blown fuse cause the P0657 code in GMC vehicles?
Yes, a blown fuse in the actuator control circuit can trigger the P0657 code and should be checked during diagnosis.
Will clearing the P0657 code with an OBDII scanner fix the problem?
Clearing the code may temporarily remove it, but the underlying issue must be repaired to prevent the code from returning.
Discuss the causes and fixes for P0657 GMC OBDII Code
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