Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Code P091, Transaxle Range Switch Problem: Actions
PCM turns on SERVICE VEHICLE SOON light. PCM disables cruise control and will substitute gear status from transaxle pressure switch for transaxle range switch.
- Checks PCM status light. AUTO should be displayed when gearshift is in Park or Neutral and OFF should be displayed if gearshift is in any other gear.
- Checks transaxle range switch for open.
- Checks circuit No. 451 for open.
- Checks circuit No. 434 for open.
- Checks if fault is still present.
- Checks for shorted transaxle range switch.
- Checks circuit No. 434 for short to ground.
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
Rather have a pro handle this?
A certified mobile mechanic comes to your home or office. They bring the tools, you stay comfortable. No tow truck, no waiting room, no surprises.
No obligation. See pricing before you book.