P0855
PowertrainTransmissionlow severityDrive Switch Input Circuit High
What P0855 Means
The PCM detects an abnormally high voltage on the drive switch input. This can cause incorrect drive mode recognition.
Symptoms
- Incorrect drive mode active
- Warning light illuminated
- Erratic transmission response
Common Causes
- Faulty drive switch
- Short to voltage in circuit
- Open circuit in wiring
- Failed control module
Diagnostic Steps
- Read stored codes
- Inspect wiring for shorts to power
- Test switch voltage across positions
- Repair wiring or replace switch
🔌 Don't have a code reader?
Any of these will read and clear this code — pick by how deep you want to go.
Budget handheld~$40
ANCEL AD410 →
No-phone-needed handheld — reads, clears, live data, freeze frame.
✓ ANCEL official store
Serious DIY~$100
BlueDriver Pro →
Enhanced codes (ABS, airbag, TPMS) plus repair reports.
SHOP FAVORITEShop-grade tablet~$300
Autel MaxiCOM MK808S →
Bidirectional tests, service resets, all systems.
✓ Autel official store
Pro diagnostics$1,500+
Autel MaxiSys MS906 Pro →
Full-system pro platform — topology mapping, ECU coding, the works.
✓ Autel official store
As an Amazon Associate and Autel/ANCEL partner, OLP earns from qualifying purchases — how we link. This never changes the specs we publish.
Community Confirmed Fixes
No confirmed fixes yet for this code. Be the first to contribute!
Submit a FixFound a Fix for P0855?
Help other technicians by sharing what worked on your vehicle.
Submit Your Fix