LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Jeep >> 1991 >> Cherokee Limited >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - System/Component Tests - Fuel Injected >> Engine Sensors & Switches >> Manifold Absolute Pressure Sensor
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Manifold Absolute Pressure Sensor

  1. Inspect MAP sensor vacuum hose connections at throttle body and sensor. Replace or repair vacuum hose if necessary.
  2. Turn ignition on, engine off. Using DVOM, check MAP sensor output voltage. On Cherokee and Comanche, connect DVOM to MAP sensor terminal "B" (Dark Green/Red wire). On Wrangler, connect DVOM to MAP sensor terminal "B" (Red/White wire).
  3. 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 engine controller wiring harness terminal No. 1. If voltage is not as specified in step 2), repair wiring harness if necessary.
  4. With ignition on, check MAP sensor supply voltage at sensor connector terminal "C" (Violet wire on Cherokee and Comanche or Brown/Yellow wire on Wrangler). Supply voltage should be 4.5-5.5 volts. Also check for supply voltage at engine controller wiring harness terminal No. 6. If supply voltage is not as specified, repair wiring harness if necessary.
  5. Check continuity of MAP sensor ground circuit at sensor connector terminal "A" (Black/Light Blue wire on Cherokee and Comanche or Brown/Red wire on Wrangler) and engine controller wiring harness terminal No. 4. Repair wiring harness if necessary.
  6. Check continuity of MAP sensor ground circuit at engine controller wiring harness terminal No. 4 and engine controller wiring harness terminal No. 11. If ohmmeter indicates an open circuit, go to next step.
  7. Check for defective sensor ground connection. Connection is located on right side of engine block, at oil dipstick tube mounting block. If ground connection is okay, replace the engine controller.
NOTE: If terminal No. 4 has a short circuit to 12 volts, correct this condition before replacing engine controller. If necessary, perform MAP sensor tests in appropriate TESTS W/CODES article in this section.
scientia non olet · About LEMON Manuals