## PGM-FI System

#### DTC Troubleshooting (cont'd)

11-64

1. Check for continuity between ECM connector terminal A1 and body ground.

ECM CONNECTOR A (31P)

Wire side of female terminals

Is there continuity?

YES - Repair short in the wire between the ECM (A1) and the primary HO2S (Sensor 1).

NO - Substitute a known-good ECM and recheck (see page 11-5). If symptom/indication goes away, replace the original ECM.

1. Measure voltage between the primary HO2S (Sensor 1) 4P connector terminal No. 3 and body ground.

PRIMARY HO2S (SENSOR 1) 4P CONNECTOR

Wire side of female terminals

Is there battery voltage?

YES - Go to step 13.

NO - Check the No. 4 ACG (10A) fuse in the under-dash fuse/relay box. If fuse is OK, repair open in the wire between the primary HO2S (Sensor 1) and No. 4 ACG (10A) fuse.

1. Turn the ignition switch OFF.

1. Reconnect the primary HO2S (Sensor 1) 4P connector.

1. Disconnect ECM connector A (31P).

1. Turn the ignition switch ON (II).

1. Measure voltage between ECM connector terminal A1 and A5.

ECM CONNECTOR A (31P)

Wire side of female terminals

Is there 0.1 V or less?

YES - Repair open in the wire between the ECM (A1) and the primary HO2S (Sensor 1).

NO - Substitute a known-good ECM and recheck (see page 11-5). If symptom/indication goes away, replace the original ECM.

a a a