Inspect MAP sensor hoses and connections. Repair 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.
To verify wiring harness condition, test ECU terminal C-6 for same voltage described. Test MAP sensor supply voltage at sensor connector terminal "C" with ignition on.
Voltage should be 4.5-5.5 volts. Same voltage should also be at terminal C-14 of ECU wire harness connector. Using Diagnostic Tester (M.S. 1170), test MAP sensor ground circuit at terminal D-3 and terminal "A" of sensor connector.
Using an ohmmeter, test MAP sensor ground circuit at ECU connector between terminal D-3 of ECU connector and terminal B-11 with an ohmmeter.
If ohmmeter or diagnostic tester indicates an open circuit, inspect for a defective sensor ground connection, located on right side of cylinder block. If ground connection is good, ECU may need to be replaced.

Fig 1: MAP Sensor 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

Map Sensor Test