On-Off Ratio Won't Adjust After Repair, MIL on

07.3-89043 On-Off Ratio Can Not be Adjusted after ALL CIS-E Engines Revised 4/90 4/89
Repair Work - Check Engine Light ON

Note
Intake and exhaust system must be tight.

Tighten all negative electrical connections as well as exhaust manifold and flange, and loosen and tighten 02 sensor. (Negative electrical connection through engine and exhaust).

Cause:

1. Intermittent or continuous malfunction of 02-sensor while driving vehicle.

2. Coaxial-cable between 02-sensor plug (G3/2x2) and CIS-E control unit pin 8 has short to ground.

3. Loose connection or intermittent interruption at connector sleeve Z (solder joint in harness) in CIS-E control unit plug.

Remedy:

1. Check on-off ratio while driving (tester needle must oscillate). If the needle of the on-off ratio tester moves slowly to the right end stop of the dial (02-sensor at operating temperature), the 02-sensor must be replaced.

2. Unplug CIS-E control unit and check resistance between socket 7 and socket 8. Nominal value: Ohm (above 10 k Ohm).

If resistance is below 1 Ohm, replace engine wiring harness.

3. Open CIS-E control unit plug and resolder connector sleeve Z (solder joint in harness) on socket 7.