P1843
1-2 Shift Solenoid Circuit High Input Voltage
Severity
⚠️ MediumCan you drive?
Limited driving only, diagnose soon
Approx. repair cost
$17–67 (est.)
Symptoms
- Problems with shifting from 1st to 2nd gear
- Jerks when shifting gears
- The gearbox goes into emergency mode
- Check Engine light comes on
- Reduced acceleration dynamics
Causes
- Open or short circuit in solenoid circuit
- Shift Solenoid 1-2 Malfunction
- Problems with the wiring harness or connectors
- Transmission control module (TCM) malfunction
- Corrosion of contacts in an electrical circuit
How to Fix
- Check the continuity of the solenoid circuit
- Check solenoid resistance
- Inspect connectors and wiring harness for damage
- If necessary, replace the 1-2 shift solenoid
- Check TCM operation