NOTE: The 1993–95, rear-wheel drive 2.4L (California)
Pick-ups have the same engine controls as the 3.0L engines. All other 2.4L engines
are listed as 2.4L engines.
- Unplug both the harness connector going to the oxygen sensor and the ECM
harness connector. Check for an open-circuit or a short-circuit to ground,
between ECM terminal 4 and the oxygen sensor terminal 1. If there is a short
or open-circuit found, repair the harness between the two terminals.
- Check for continuity of the ground circuit (oxygen sensor connector terminal
2). If there is continuity, the harness is good, otherwise repair the harness
between oxygen sensor terminal 2 and the ground.
| Fig. 1: The O2sensor harness connector terminals — 2.4L
engines
|
- Unplug the MFI relay connector and the oxygen sensor connector. By touching
the ohmmeter probes to both ends of the harness, check for continuity between
the O2sensor and the MFI relay terminals. If no continuity is found, repair
or replace the harness between the two terminals.
- 3.0L (12 valve) engines: MFI terminal 5 and O2sensor terminal 1.
- 3.0L (24 valve) and 3.5L engines: MFI terminal 3 and O2sensor terminal
1.
- Unplug the ECM harness connector and plug the MFI relay connector back in.
Check for an open-circuit or a short-circuit to ground between the O2sensor
and the ECM. If there is a short or open-circuit, repair or replace the harness
between the two terminals.
- 3.0L (12 valve) engines: ECM terminal 4 and O2sensor terminal 4.
- 3.0L (24 valve) and 3.5L engines: ECM terminal 56 and O2sensor terminal
4.
- Check for continuity in the ground circuit. If no continuity is found, repair
or replace the harness between the terminals.
- 3.0L (12 valve) engines: ECM terminal 17 and 24 and O2sensor terminal
2, Ground circuit and O2sensor terminal 3.
- 3.0L (24 valve) and 3.5L engines: ECM terminal 72 and O2sensor terminal
2, Ground circuit and O2sensor terminal 3.
| Fig. 2: The O2sensor harness connector terminals — 3.0L
and 3.5L engines
|
