Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means that the car's computer is being told by the transmission to reduce the engine's power to keep things safe.
The Transmission Control Module (TCM) has sent a request to the engine control module to reduce torque as a safety measure.
The P1ACF code is triggered when the TCM requests the Engine Control Module (ECM) to reduce engine torque. This is typically a safety function to protect the transmission from damage or to ensure smooth operation under certain conditions.
• Reduced engine performance
• Check Engine Light is on
• Transmission may not shift properly
• Faulty Transmission Control Module (TCM)
• Wiring issues between TCM and ECM
• Software issue in the control modules
TCM: Transmission Control Module
ECM: Engine Control Module
OBD-II: On-Board Diagnostics, Second Generation
• Use an OBD-II scanner to confirm the code.
• Inspect the wiring and connections between the TCM and ECM.
• Check for any software updates or recalls for the TCM or ECM.
• Repair or replace faulty wiring or connectors.
• Reprogram or update the software in the TCM or ECM.
• Replace the TCM if it's determined to be faulty.
• OBD-II Scanner
• Multimeter
• Diagnostic software tool
$150 - $600
Moderate
• Chevrolet Volt
• Cadillac ELR
• Buick LaCrosse
• Regular maintenance of the transmission system
• Ensure software is up-to-date
• Avoid aggressive driving habits
Transmission Control Issue
• Drive gently until the issue is resolved.
• Consult with a professional mechanic for a thorough diagnosis.
Check with your vehicle manufacturer for warranty coverage on transmission components.
This code has been associated with hybrid and electric vehicles where precise torque management is crucial.
Moderate – While the vehicle may still be drivable, it is important to address this issue to prevent further damage.
Ignoring this code can lead to transmission damage, which may result in higher repair costs and potential safety issues.
• Vehicle must be running.
• Transmission must be engaged.
The Transmission Control Module is typically located near the transmission or within the engine bay.
Q: Can I drive with a P1ACF code?
A: It's possible, but not recommended. Reduced engine performance can affect drivability and may lead to further damage.
Q: What happens if I ignore this code?
A: Ignoring the code can lead to transmission damage and potentially higher repair costs.
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