What Does P1766 Mean?
The transmission control module is receiving a throttle position signal that appears stuck at a closed or zero position. This prevents proper transmission shift scheduling based on driver demand.
Common Causes
35%
Failed throttle position sensor or accelerator pedal position sensor
30%
Open circuit or poor connection in TPS signal wire to TCM
20%
Communication fault between engine control module and TCM
10%
TCM internal fault preventing throttle signal reception
5%
Corroded or damaged connector at TPS or TCM
Diagnostic Steps
1
Step 1: Use scan tool to monitor throttle position angle in live data while operating accelerator pedal (should vary 0-100%)
2
Step 2: Compare throttle angle data between engine control module and transmission control module parameters
3
Step 3: Inspect TPS/APP sensor connector for corrosion, damage, or loose terminals
4
Step 4: Check wiring continuity between TPS and TCM, or verify CAN bus communication between ECM and TCM
5
Step 5: Test throttle position sensor voltage output directly at sensor (should vary smoothly 0.5-4.5V)
Estimated Repair Cost
$100 - $600
Parts + labor, varies by vehicle and location
The transmission control module is receiving a throttle position signal that appears stuck at a closed or zero position. This prevents proper transmission shift scheduling based on driver demand.
The most common cause of P1766 (Throttle Angle Signal Stuck Off) is: Failed throttle position sensor or accelerator pedal position sensor
Typical repair costs for P1766 range from $100 to $600, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Transmission may not downshift for acceleration or upshift appropriately, causing unexpected vehicle behavior and potential loss of power when needed.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P1766 to identify the root cause.
OBDHut Mobile App
Scan codes directly from your car with the OBDHut app.
Coming Soon
Quick Info
Category
Powertrain
System
Automatic Transmission
Difficulty
Type
Manufacturer
Recommended Tools
OBD2 Scanner
A quality scan tool helps you read codes, view live data, and clear faults.
