Turn the ignition switch OFF. Disconnect the manifold absolute pressure (MAP) sensor 3P connector. Turn the ignition switch ON (II). Measure voltage between body ground and ECM connector terminal A21. ECM CONNECTOR A (31P) Wire side of female terminals Is there about 5 V? YES - Replace the MAP sensor. NO - Go to step 64. Turn the ignition switch OFF. Disconnect ECM connector A (31P).

Check for continuity between ECM connector terminal A21 and body ground. ECM CONNECTOR A (31P) Wire side of female terminals Is there continuity? YES - Repair short in the wire between the ECM (A21) and the MAP sensor. NO - Substitute a known-good ECM and recheck (see page 11-5). If symptom/indication goes away, replace the original ECM. Measure voltage between body ground and ECM connector terminal A20. Is there about 5 V? YES - Substitute a known-good ECM and recheck (see page 11-5). If symptom/indication goes away, replace the original ECM. NO - Go to step 68. aaa