What Does P1901 Mean?
The transfer case disengaged solenoid circuit has a short to ground condition. This prevents proper control of the transfer case disengagement function and may cause 4WD engagement issues.
Common Causes
35%
Failed transfer case shift solenoid with internal short
30%
Damaged wiring harness with wire grounding to transfer case housing
20%
Corroded or moisture-damaged solenoid connector
15%
Transfer case control module internal driver circuit failure
Diagnostic Steps
1
Step 1: Disconnect transfer case disengagement solenoid connector and measure resistance to ground
2
Step 2: Inspect wiring harness routing near transfer case for damage or contact with hot/moving parts
3
Step 3: Test solenoid coil resistance and compare to specifications
4
Step 4: Check control module solenoid driver circuit with solenoid disconnected for internal shorts
5
Step 5: Inspect transfer case for fluid leaks that may have contaminated solenoid or connector
Estimated Repair Cost
$200 - $700
Parts + labor, varies by vehicle and location
The transfer case disengaged solenoid circuit has a short to ground condition. This prevents proper control of the transfer case disengagement function and may cause 4WD engagement issues.
The most common cause of P1901 (Transmission Transfer Case Disengaged Solenoid Short to Ground) is: Failed transfer case shift solenoid with internal short
Typical repair costs for P1901 range from $200 to $700, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Transfer case may not disengage from 4WD properly, causing drivetrain binding on dry pavement. Avoid tight turns and reduce speed until repaired.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P1901 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
Four-Wheel Drive Transfer Case
Difficulty
Type
Manufacturer
Recommended Tools
OBD2 Scanner
A quality scan tool helps you read codes, view live data, and clear faults.
