Inspect MAP sensor hoses and connections. Repair or replace as necessary. With ignition on and engine off, test MAP sensor output voltage at connector terminal "B". (marked on sensor body). See Fig 1 . Output voltage should be 4 to 5 volts. Voltage should drop to 1.5-2.1 volts when vehicle is hot, and idling in Neutral. To verify wiring harness condition, test ECU terminal C-6 for same voltage as described. Repair or replace wire as necessary.
Test MAP sensor supply voltage at MAP sensor connector terminal "C" with ignition on. There should be between 4.5-5.5 volts present. To verify wiring harness condition, test ECU terminal C-14 for same voltage as described. Repair or replace as necessary.
Test MAP sensor ground circuit at ECU connector between terminal D-3 and terminal B-11 using an ohmmeter. If ohmmeter indicates an open circuit, inspect for defective sensor ground connection (located on right side of block, on oil dipstick mounting stud). If ground connection is good, check terminal D-3 for short to battery voltage and correct short if necessary. If terminal D-3 reads battery voltage, replace ECU.

Fig 1: MAP Sensor Connector Test Points

Courtesy of CHRYSLER MOTORS.

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.

Safety Warning

Manifold Absolute Pressure (MAP) Sensor Test