Fault TRACINGB230F/FT 1985 M/Y-

The air mass meter for above model years has a black housing. The housing is marked with Bosch Part No. 0 280 212 007.

Connector configuration as illustrated.


CAUTION: The two types of air mass meters described in this Service Bulletin are not interchangeable.



Check ground(s)

- Connect an ohm-meter between terminal 1 and ground, and between terminal 2 and ground.

Meter should show less than 1 ohm resistance in both cases. Check wiring continuity if value is higher.



Check voltage supply

- Turn ignition ON.

- Connect a volt meter between terminal 5 and ground.

Meter should show battery voltage. Check wiring continuity and fuel system relay if lower than battery voltage.



Check CO-adjustment screw

- Turn ignition ON.
- Connect a volt meter between terminal

14 at the LH control unit and ground.

Meter should show 0 to 2.6 volts depending on CO-screw position.

0 volts = max. lean position
2.6 volts = max. rich position

- Turn screw on air mass meter and check if voltage changes.

If no voltage or no variation when screw is turned, check wiring continuity.


NOTE: Adjustment screw must be resealed after adjustment.



Check air mass meter output

- Turn ignition ON.

- Connect a voltmeter between terminal 7 at the LH control unit and ground.

Meter should show 1.2 volts.

- Start engine and warm up to operating temperature (AC off).

- Check output at idle (750 rpm). Meter should show 2.2 volts.

- Increase engine speed to 3,500 rpm. Output should increase to 2.9 volts. Check wiring continuity if out of specification.



Burn off function

Engine running at operating temperature.

- Connect a volt meter between terminal 4 and ground.
- Increase engine speed to 2,500 rpm.

- Close throttle and let engine slow down to idle speed.

- Turn ignition OFF.

After approximately 4 seconds, the meter should deflect for 1 second. If no reading, check wiring continuity.


INSTALL

- rubber connector cover at air mass meter

- connector cover at LH control unit
- kick panel
Warranty Claims may be submitted during the new car warranty period for diagnosis.

Operation Number: 238623 Time Allowance: 0.8 hours