What Does C1945 Mean?
The transmission park position switch is indicating the vehicle is in Park, but the ABS/stability control module detects wheel speed indicating the vehicle is moving. This contradictory signal suggests the park switch is stuck, misadjusted, or has a circuit fault. This code can affect shift interlock operation, stability control logic, and automatic parking brake features. The driver may notice transmission shift indicator showing P while driving.
Common Causes
35%
Faulty transmission range sensor (TRS) or park/neutral position switch stuck indicating Park
25%
Transmission range sensor misadjusted after transmission service or replacement
20%
Wiring fault in the park switch circuit — short to ground creating a false park signal
15%
Shift linkage or cable out of adjustment causing the TRS to report incorrect position
5%
ABS/ESC module receiving corrupted transmission position data via CAN bus
Diagnostic Steps
1
Monitor the transmission range/gear position PID in live data while shifting through all gears. Verify the displayed gear matches the actual shifter position in each gear. Pay special attention to the transition out of Park.
2
Inspect the shift linkage and cable from the shifter to the transmission. Verify proper adjustment — the linkage should have no excess play and the detents should align with the transmission manual valve positions.
3
At the transmission range sensor connector, check the signal voltage or resistance (per service manual spec) in each gear position. In Park, verify the expected value, then shift to Reverse and Drive, confirming distinct changes.
4
Check for water intrusion or corrosion at the transmission range sensor connector, which is commonly exposed to road spray and moisture.
5
If the sensor readings are correct at the connector but the module still reports Park while driving, check the CAN bus communication between the TCM and ABS module. The TCM may be providing incorrect data.
Estimated Repair Cost
$50 - $350
Parts + labor, varies by vehicle and location
The transmission park position switch is indicating the vehicle is in Park, but the ABS/stability control module detects wheel speed indicating the vehicle is moving. This contradictory signal suggests the park switch is stuck, misadjusted, or has a circuit fault. This code can affect shift interloc...
The most common cause of C1945 (Park Switch Indicates Park with Vehicle Moving) is: Faulty transmission range sensor (TRS) or park/neutral position switch stuck indicating Park
Typical repair costs for C1945 range from $50 to $350, depending on the vehicle, location, and whether you do it yourself or go to a shop.
The vehicle can be driven, but stability control algorithms may not function correctly because the module believes the vehicle is stationary in Park. On some vehicles, the automatic parking brake or shift interlock may behave unexpectedly. Repair soon to restore proper safety system operation.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to C1945 to identify the root cause.
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Quick Info
Category
Chassis
System
Transmission / Stability Control
Difficulty
Type
Manufacturer
Recommended Tools
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