What Does P1717 Mean?
The transmission is unable to properly communicate torque reduction requests to the engine control module, or the signal circuit is malfunctioning. This coordination is critical for smooth shifts under load.
Common Causes
35%
Communication network fault between TCM and ECM
25%
Failed transmission control module
20%
Failed engine control module
15%
Damaged wiring or connectors in torque reduction signal circuit
5%
Software calibration mismatch between TCM and ECM
Diagnostic Steps
1
Step 1: Check for additional communication-related DTCs in both TCM and ECM
2
Step 2: Inspect TCM and ECM connectors for corrosion, damage, or loose connections
3
Step 3: Test CAN bus circuit continuity and resistance between control modules
4
Step 4: Monitor torque reduction signal with bidirectional controls during test drive
5
Step 5: Verify TCM and ECM software versions are compatible and up to date
Estimated Repair Cost
$150 - $1,500
Parts + labor, varies by vehicle and location
The transmission is unable to properly communicate torque reduction requests to the engine control module, or the signal circuit is malfunctioning. This coordination is critical for smooth shifts under load.
The most common cause of P1717 (Trans Torque Reduction Request Signal Malfunction) is: Communication network fault between TCM and ECM
Typical repair costs for P1717 range from $150 to $1,500, depending on the vehicle, location, and whether you do it yourself or go to a shop.
May cause harsh or abrupt shifts, especially under acceleration. Can lead to driveline shock loads and reduced shift quality.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P1717 to identify the root cause.
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Quick Info
Category
Powertrain
System
Transmission Control / Engine Management
Difficulty
Type
Manufacturer
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