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: Notes
This test monitors the park/neutral input from transaxle range switch to PCM (PD72). Transaxle range switch also sends information relative to gear selection to instrument panel cluster (ID41). PCM compares the two decoded signals and if PCM detects a fault in one of the decoded signals or engine starts with no park/neutral input, or if vehicle is in forth gear and engine speed divided by vehicle speed is between 23 RPM/MPH, and park/neutral input indicates park/neutral Code P091, then Code I027 will set.
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra 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.