What Does C1277 Mean?
The powertrain control module (PCM) has communicated a traction control malfunction to the ABS/TCS module via the data bus. This code indicates the PCM is unable to perform its portion of traction control — typically engine torque reduction — when requested by the EBCM. The driver will see the TCS warning light and traction control will be inoperative.
Common Causes
30%
PCM-side fault: stored powertrain DTC preventing TCS torque reduction cooperation
25%
Communication fault between PCM and EBCM on the serial data bus
20%
Throttle actuator control (TAC) or electronic throttle body malfunction
15%
EBCM internal fault misinterpreting PCM traction data
10%
Engine misfire or fueling issue causing PCM to disable TCS cooperation
Diagnostic Steps
1
Check for powertrain DTCs (P-codes) in the PCM first — this chassis code is almost always secondary to a powertrain fault. Common culprits include throttle body codes (P2101, P2135) or misfire codes.
2
Monitor the serial data bus communication between the PCM and EBCM using live data — verify that TCS torque request and TCS torque delivered values are present and responding.
3
If no P-codes are present, inspect the CAN bus wiring between the PCM and EBCM for damage, shorts, or opens. Measure bus resistance at the DLC (should be approximately 60 ohms between CAN-H and CAN-L).
4
With the engine running, command a TCS event using bidirectional controls (if available) and monitor whether the PCM responds with torque reduction — no response confirms the PCM communication path.
5
Check for TSBs specific to the vehicle for PCM calibration updates that address TCS communication handshake issues.
Estimated Repair Cost
$100 - $1,000
Parts + labor, varies by vehicle and location
The powertrain control module (PCM) has communicated a traction control malfunction to the ABS/TCS module via the data bus. This code indicates the PCM is unable to perform its portion of traction control — typically engine torque reduction — when requested by the EBCM. The driver will see the TCS w...
The most common cause of C1277 (Powertrain Indicated Traction Control Malfunction) is: PCM-side fault: stored powertrain DTC preventing TCS torque reduction cooperation
Typical repair costs for C1277 range from $100 to $1,000, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Traction control is disabled. The vehicle can be driven normally, but there will be no electronic traction control intervention during wheel spin events. Be cautious on slippery roads and during aggressive acceleration. ABS braking typically remains functional. Diagnose and repair the underlying powertrain fault to restore TCS operation.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to C1277 to identify the root cause.
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Quick Info
Category
Chassis
System
ABS / Traction Control
Difficulty
Type
Manufacturer
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