P1845: Transfer Case Shift Motor Circuit Short to Battery
The P1845 code indicates a short to battery voltage in the transfer case shift motor circuit. The control module has detected excessive voltage on the motor drive circuit when it should not be present. This fault prevents the four-wheel drive (4WD) system from properly engaging the transfer case to shift modes (e.g., from 2H to 4H or 4L).
01. Most Common Causes
- Short to voltage in the transfer case shift motor wiring harness
- Damaged or internally shorted transfer case shift motor
- Corroded or bent pins in the shift motor connector
- Faulty transfer case control module (4WD ECU)
- Water or moisture damage in the electrical circuit
02. Symptoms You Will Notice
- Inability to shift between 2WD and 4WD modes
- 4WD warning light illuminated on the dashboard
- Transfer case stuck in one mode (e.g., 2H or 4H)
- Grinding or clicking noises from the transfer case area
03. Step-by-Step Diagnosis
Scan for additional codes and verify P1845 is present
Visually inspect the shift motor wiring and connector for damage, corrosion, or bent pins
Test the shift motor circuit for short to battery voltage using a multimeter
Check the shift motor resistance and operation per manufacturer specifications
If wiring and motor are OK, test the transfer case control module for proper output signals
1. Frequently Asked Questions
Is it safe to drive?▼
Driving is not recommended because the 4WD system may fail to engage or disengage unexpectedly, potentially causing loss of control or driveline damage. Have the vehicle towed to a repair shop.
How much does it cost to fix?▼
Repair costs typically range from $200 to $800, depending on whether the issue is a simple wiring repair or requires replacement of the shift motor or control module.