What Does B1750 Mean?
This code indicates the Body Control Module (BCM) or Transmission Control Module (TCM) has detected an open circuit in the Park/Neutral Position (PNP) switch wiring or sensor. The PNP switch signals to the vehicle's control modules when the transmission is in Park or Neutral, which is critical for starting the vehicle and various safety systems. An open circuit means no signal is being received, preventing proper system operation.
Safety Warning
Vehicle may not start or may start in gears other than Park/Neutral, creating a serious safety hazard. Backup lights and cruise control may also be affected. Repair immediately as the vehicle could unexpectedly move when starting.
Common Causes
40%
Faulty or failed Park/Neutral Position switch internal contacts or mechanism
30%
Broken, corroded, or disconnected wiring harness between PNP switch and control module
20%
Corroded or loose electrical connector at the PNP switch
10%
Misadjusted or improperly installed Park/Neutral Position switch causing intermittent contact
Diagnostic Steps
1
Step 1: Perform visual inspection of the Park/Neutral Position switch connector and wiring harness for obvious damage, corrosion, disconnection, or chafing. Check connector security and terminal pin condition.
2
Step 2: Using a digital multimeter, backprobe the PNP switch connector and check for continuity between switch terminals while cycling the shifter through all gear positions. Verify switch operation matches manufacturer specifications (typically closed circuit in Park and Neutral).
3
Step 3: If switch tests normally, check wiring continuity from the PNP switch connector back to the BCM/TCM connector using a multimeter. Test for open circuits, shorts to ground, or shorts to power on all relevant circuits.
4
Step 4: If wiring is intact, measure voltage supply to the PNP switch from the control module (typically 5V or 12V reference). If no voltage present, suspect control module or related power supply circuit fault.
5
Step 5: If all electrical tests pass, verify proper mechanical adjustment and alignment of the PNP switch to the transmission shift linkage. Adjust per manufacturer specifications if needed.
6
Step 6: After repairs, clear codes, cycle the shifter through all positions multiple times, and verify the code does not return. Test vehicle start function in Park and Neutral only.
Estimated Repair Cost
$120 - $450
Parts + labor, varies by vehicle and location
This code indicates the Body Control Module (BCM) or Transmission Control Module (TCM) has detected an open circuit in the Park/Neutral Position (PNP) switch wiring or sensor. The PNP switch signals to the vehicle's control modules when the transmission is in Park or Neutral, which is critical for s...
The most common cause of B1750 (Park/Neutral Switch Circuit Open) is: Faulty or failed Park/Neutral Position switch internal contacts or mechanism
Typical repair costs for B1750 range from $120 to $450, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Vehicle may not start or may start in gears other than Park/Neutral, creating a serious safety hazard. Backup lights and cruise control may also be affected. Repair immediately as the vehicle could unexpectedly move when starting.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B1750 to identify the root cause.
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Quick Info
Category
Body
System
Transmission Control and Starting System
Difficulty
Type
Manufacturer
Recommended Tools
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