MAP Sensor Test
- Inspect the MAP sensor hoses and connections. Repair as necessary. With the ignition on and the engine off, test the MAP sensor output voltage at the MAP sensor connector terminal "B" (marked on sensor body). See Fig 1
. The output voltage should be 4 to 5 volts.
- To verify the wiring harness condition, test ECU terminal C-6 for the same voltage described. Test MAP sensor supply voltage at the sensor connector terminal "C" with the ignition on.
- The voltage should be 4.5-5.5 volts. The same voltage should also be at terminal C-14 of the ECU wire harness connector. Using a Diagnostic Tester (M.S. 1170), test MAP sensor ground circuit at terminal D-3 and terminal "A" of sensor connector.
- Using an ohmmeter, test the MAP sensor ground circuit at the ECU connector between terminal D-3 of ECU connector and terminal B-11 with an ohmmeter.
- If the ohmmeter or diagnostic tester indicates an open circuit, inspect for a defective sensor ground connection, located on the right side of the cylinder block. If the ground connection is good the ECU may need to be replaced.
Courtesy of AMERICAN MOTORS/JEEP CORP.