Speakers - Pop, Erratic A/C Display, Engine Misfires

9232audi01

Group: 87

Number: 92-02

Date: 04/08/92


Subject:
Pop Or Click In BOSE Speakers, Incorrect Or Erratic A/C Control Head Display, Engine Missfires - When A/C Clutch Disengages

Model(s):
100/200/V8/80/90
M.Y. 1988-1991


THIS TECHNICAL BULLETIN SUPERSEDES TECHNICAL BULLETIN GROUP 87, 91-05, 06/30/91.


Condition

Decay of magnetic field in A/C clutch may cause a voltage peak.

- A pop or click may be heard in the BOSE speakers when A/C clutch cycles/turns off.
- Temperature display may change or surpass normal range.
- Backfire from engine and/or fault G28 in engine fault memory.


Production

A/C compressor clutch modified with zener diode and improved A/C compressor clutch control relay
As of: November 1990
VIN:
44 MN 024 295
4C MN 001 831





Service

- Install compressor clutch control relay Part No. 443 919 578H.
- Install Zener diode kit Part No. 441 298 008.

Note
Kit may come in two configurations.

Version 1

This version has a complete harness with connectors attached to the diode.

- Disconnect connector between compressor clutch and compressor clutch control relay and install diode harness in between.

- Mount diode (arrow) and bracket on compressor as shown using a 5mm screw.


Version 2

This version has no connectors attached to diode lead.

Additional parts required:
Terminal Part No. N 017 461 4
Insulation Tubing locally available


- Run diode lead through insulation tubing. (3mm tubing approx. 140mm long.)

- Disconnect connector between compressor clutch and compressor clutch control relay.

- Cut compressor connector off (keep the hard shell connector!) and run this lead together with diode lead through insulation tubing. (5mm tubing approx. 160mm long)

- Crimp terminal (Part No. 017 461 4) to both diode and compressor lead.

- Slip terminal into the old hard shell connector.

- Reconnect the connectors.

- Mount diode (arrow) and bracket on compressor as shown using a 5mm screw.


Note

- If A/C control head display still shows incorrect temperature range after diode and A/C clutch control unit have been installed, display unit may have to be replaced.

- Erase engine ECM fault memory after repair.