Inspect MAP sensor vacuum hose connection at throttle body and sensor. Repair as required.
Turn ignition switch to the "ON" position (engine not running). Test MAP sensor output voltage at MAP sensor terminal "B" (as marked on sensor body). See Fig 1 . Output voltage should be 4.0-5.0 volts.
NOTE: Voltage should drop 1.5-2.1 volts at idle with engine at operating temperature.
Test voltage at pin No. 33 of ECU connector for 4.0-5.0 volts to verify wiring harness condition. See Figure . Repair as required.
Turn ignition switch to the "ON" position. Check for MAP sensor supply voltage of 4.5-5.5 volts at sensor connector terminal "C". Similar voltage should be present at ECU connector pin No. 16. Repair or replace wiring harness if required. Test for sensor ground between ECU connector pin No. 17 and MAP sensor connector terminal "A". See Fig 1 .
Using an ohmmeter, check for ground between ECU connector pin No. 17 and pin No. 2. If an open circuit is indicated, check for a defective sensor ground in the flywheel housing near starter motor.
If ground is good, ECU must be replaced. Before replacing ECU, see if voltage exists at ECU connector pin No. 17. If so, repair condition prior to replacing ECU.

Fig 1: MAP Sensor Terminal Identification

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