Manifold Absolute Pressure (Map) Sensor
- Inspect MAP sensor vacuum hose connections at throttle body and sensor. Replace or repair vacuum hose if necessary.
- Turn ignition on with engine off. Using DVOM, check MAP sensor output voltage. On Wrangler, connect DVOM to MAP sensor terminal "B" (Dark Green/Red wire) and ground. Terminal identification letters/numbers are marked on sensor body.
- Output voltage should be 4-5 volts. Voltage should drop to 1.5-2.1 volts with a hot engine operating in Neutral and at idle speed. Also check for output voltage at PCM wiring harness terminal No. 1 on Wrangler. If voltage is not as previously specified, repair wiring harness as necessary.
- Turn ignition on. Check MAP sensor supply voltage at Violet/White wire at sensor connector "C". Supply voltage should be 4.5-5.5 volts. Also check for supply voltage at PCM wiring harness terminal No. 6. If supply voltage is not as specified, repair wiring harness if necessary.
- Check continuity of MAP sensor ground circuit (Black/Light Blue wire) between sensor connector terminal "A" and PCM wiring harness terminal No. 4. If continuity does not exist, repair wiring harness.
- Check continuity of MAP sensor ground circuit between PCM wiring harness terminals No. 4 and 11. If ohmmeter indicates an open circuit, go to next step. If ground connection is okay, replace PCM.NOTE: If terminal No. 4 has a short circuit to 12 volts, correct this condition before replacing PCM. If necessary, perform MAP sensor tests in TESTS W/CODES - 2.5L & 4.0L article in this section.
- Check for defective sensor ground connection. Connection is located on right side of engine block, at oil dipstick tube mounting block. Repair connection as necessary.