Checking Map Sensor Calibration
NOTE:
For circuit identification and wiring diagram, see WIRING DIAGRAMS article. After each repair procedure has been completed, reconnect all components. Perform appropriate verification test to ensure system is functioning properly. On Cherokee and Wrangler, perform TEST VER-2
under VERIFICATION TESTS to ensure system is functioning properly. On Grand Cherokee, perform TEST VER-5
under VERIFICATION TESTS.
Turn ignition off. Install vacuum "T" fitting and vacuum gauge at vacuum source on intake manifold. Start engine and allow engine to idle. If engine will not idle, maintain a constant RPM above idle. Note engine vacuum on vacuum gauge. Using scan tool, read MAP sensor vacuum. If MAP sensor vacuum is within one in. Hg of engine vacuum on vacuum gauge, MAP sensor is operating properly. Test is complete. If MAP sensor vacuum is not within one in. Hg of engine vacuum on vacuum gauge, replace MAP sensor.