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.
SYS.OK|MANUAL.DB● LIVE
HOMESERVICE MANUALSJEEP1991CHEROKEE 2WD L4-150 2.5L VIN P MFIREPAIR AND DIAGNOSISPOWERTRAIN MANAGEMENTCOMPUTERS AND CONTROL SYSTEMSBRAKE SIGNALDESCRIPTION AND OPERATION
1991 Jeep Cherokee 2WD L4-150 2.5L VIN P MFI
Brake Signal: Description and Operation
1991 Jeep Cherokee 2WD L4-150 2.5L VIN P MFISECTION Description and Operation
The brake light switch is used as an engine controller input to signal deceleration and full stop conditions. The engine controller uses brake switch input to maintain idle at a scheduled rpm. It does this by sending signals to the Automatic Idle Speed (AIS) Motor, positioning it according to the scheduled rpm. This sensor is also used to shut off the speed control in the event of brake application.
RENDER: 1.0x
NO RELATED
Recommended Tools & Savings
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.