What Does P1810 Mean?
DTC P1810 has a dual definition depending on manufacturer. It can indicate a TFP (transmission fluid pressure) valve position switch circuit malfunction or a 4WD low indicator short to battery. In the TFP context, the switch provides gear position feedback to the TCM. In the 4WD context, the low-range indicator circuit is being fed unwanted voltage. Both conditions affect critical drivetrain control feedback.
Common Causes
25%
Failed TFP valve position switch (stuck or erratic)
25%
Shorted 4WD low indicator wiring contacting a power source
20%
Corroded or damaged connector at the transmission or transfer case
15%
Contaminated transmission fluid affecting pressure switch operation
15%
TCM or TCCM internal circuit fault
Diagnostic Steps
1
Identify which definition applies to your vehicle using manufacturer-specific service information.
2
For TFP switch: Monitor the TFP switch state PIDs on the scan tool while shifting through all gears; each position should show a unique valid state.
3
For 4WD low indicator: Disconnect the transfer case connector and check for battery voltage on the indicator signal wire.
4
Inspect the relevant connector for corrosion and damage; clean and re-seat as needed.
5
For TFP issues, check transmission fluid condition; contaminated fluid can cause pressure switch malfunctions.
6
Test the switch assembly with an ohmmeter according to manufacturer pin charts for each position.
Estimated Repair Cost
$100 - $700
Parts + labor, varies by vehicle and location
DTC P1810 has a dual definition depending on manufacturer. It can indicate a TFP (transmission fluid pressure) valve position switch circuit malfunction or a 4WD low indicator short to battery. In the TFP context, the switch provides gear position feedback to the TCM. In the 4WD context, the low-ran...
The most common cause of P1810 (TFP Valve Position Switch Circuit/ Transmission 4-Wheel Drive Low Indicator Short Circuit To Battery) is: Failed TFP valve position switch (stuck or erratic)
Typical repair costs for P1810 range from $100 to $700, depending on the vehicle, location, and whether you do it yourself or go to a shop.
A faulty TFP switch can cause incorrect gear selection and harsh shifts. A false 4WD-Low indication can mislead the driver about the active drive mode, affecting vehicle handling expectations.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P1810 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
Transmission / Transfer Case
Difficulty
Type
Manufacturer
Recommended Tools
OBD2 Scanner
A quality scan tool helps you read codes, view live data, and clear faults.
