Pinpoint Test Q
Enter this pinpoint test only when directed from KEY ON, ENGINE RUNNING or KEY ON, ENGINE OFF SELF-TEST. This pinpoint test is intended to diagnose only the ECA and harness circuits (signal return, STO, STI, and ground).
- Turn key off and wait 10 seconds. Disconnect ECA 60-pin connector and inspect for damage. Service as necessary. Install Breakout box, leaving ECA disconnected. Set DVOM to 200-ohm scale. Measure resistance between SELF-TEST input at SELF-TEST single pin connector and test pin 48 at Breakout box. If less than 5 ohms, go to next step. If greater than 5 ohms, correct open in circuit.
- Install Breakout box. Set DVOM to 200-ohm scale. Measure resistance between SELF-TEST output at SELF-TEST connector and test pin 17 at Breakout box. If less than 5 ohms, go to next step. If greater than 5 ohms, correct open in circuit.
- Install Breakout box. Turn key off. Measure resistance between EGO ground on engine and test pin 49 at Breakout box. If less than 5 ohms, go to next step. If greater than 5 ohms, check and service EGO sensor ground wire or open circuit.
- Install Breakout box. Set DVOM on 200,000-ohm scale. Measure resistance between SELF-TEST output at SELF-TEST connector and engine block ground. If resistance is greater than 10,000 ohms, replace ECA and repeat QUICK TEST . If not, service shorts to ground and repeat QUICK TEST. See Fig 1 .