Technical Service Bulletin
87 Air conditioning inoperative
87 12 37 2020124/8 November 16, 2012. Supersedes Technical Service Bulletin Group 87 number 12-32 dated
September 5, 2012 for reasons listed below.
Model(s)

Year

VIN Range

A4

2009-2011

All

A5, S5

2008-2011

All

Cabrio

2010-2011

All

A6

2005-2011

All

A8

2004-2010

All

Vehicle-Specific Equipment

Not Applicable

Condition
REVISION HISTORY
Revision

Date

Purpose

8

-

Revised header data (added D3 pull ahead)
Revised Service
Revised Warranty (Additional SRT)

7

9/5/2012

Revised Service (Added labels a-d)
Revised Warranty

6

7/23/2012

Revised Service (Added an additional descriptive note and text)

5

8/15/2011

Revised Service (Added additional steps and images)
Revised Warranty

4

4/8/2011

Revised Condition, Technical Background, Production Solution

3

3/22/2011

Revised header data (Added models and model years)
Revised Technical Background, Production Solution, Service, and

Required Parts and Tools
2

4/23/2010

Revised Technical Background, Production Solution, and Service

Page 1 of 9
© 2012 Audi of America, Inc.
All rights reserved. Information contained in this document is based on the latest information available at the time of printing and is subject to the copyright and other intellectual property rights
of Audi of America, Inc., its affiliated companies and its licensors. All rights are reserved to make changes at any time without notice. No part of this document may be reproduced, stored in a
retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, nor may these materials be modified or reposted to other sites, without
the prior expressed written permission of the publisher.

Technical Service Bulletin
1

2/27/2009

Original publication

 Air conditioning is inoperative.
 The HVAC blower functions normally.
 Battery discharged; however, when charged, there is no bus silence when vehicle ignition is off.

Technical Background
 The A/C Pressure/Temperature Sensor G395 leaks refrigerant. This causes Sensor G395 to show an
incorrect or implausible value when reading MVBs. An incorrect signal or a low refrigerant level in the system
can cause the air conditioning compressor to deactivate.
 The LIN cable connecting the J519 Central Electrics Control unit to Sensor G395 is pinched or cut. This
affects the A4/S4, A5/S5 Coupe and Cabriolet, and Audi Q5 vehicles. The A6 and A8 are not affected by this
type of failure.
 The pressure sensor G395/G65 sends an incorrect signal that prevents bus silence and the battery is
discharged.
Tip: Sensor G395 is a LIN slave of Vehicle Electrical System Control Module J519. Vehicle Electrical
System Control Module J519 transfers the information provided by the sensor via the comfort data bus to
Climate Control Module J255.

Production Solution
An improved A/C Pressure/Temperature Sensor G395 was introduced into series production and the wiring
manufacturer’ s processes were optimized.

Service
For A4/S4 (8K), A5/S5 Coupe/Cabriolet (8T/8F), Audi Q5, A6, A8:
If DTCs are stored in the J255 Climate Control Module for the G395 pressure sensor, then check the system
pressures and refrigerant volume.

Page 2 of 9
© 2012 Audi of America, Inc.
All rights reserved. Information contained in this document is based on the latest information available at the time of printing and is subject to the copyright and other intellectual property rights
of Audi of America, Inc., its affiliated companies and its licensors. All rights are reserved to make changes at any time without notice. No part of this document may be reproduced, stored in a
retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, nor may these materials be modified or reposted to other sites, without
the prior expressed written permission of the publisher.

Technical Service Bulletin
 If system pressures and refrigerant volume are low, check for refrigerant leaks at G395. If a leak is found, then
replace the G395.
 If the system pressure and refrigerant volume are correct, perform guided fault finding. If an implausible
pressure value is found in MVB 1, field 4, then replace G395.
Tip: Install only the improved G395. See part numbers in Required Parts and Tools.

Page 3 of 9
© 2012 Audi of America, Inc.
All rights reserved. Information contained in this document is based on the latest information available at the time of printing and is subject to the copyright and other intellectual property rights
of Audi of America, Inc., its affiliated companies and its licensors. All rights are reserved to make changes at any time without notice. No part of this document may be reproduced, stored in a
retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, nor may these materials be modified or reposted to other sites, without
the prior expressed written permission of the publisher.

Technical Service Bulletin
Only for A4/S4 (8K), A5/S5 Coupe/Cabriolet (8T/8F), Audi Q5:
1. Check the diagnostic fault memory for two possible DTC scenarios:

DTC Scenario 1

08 - Climate Control Module - J255:
DTC 00457 - Vehicle Electrical System Control Module – J519- Please check DTC memory
DTC 00256 - A/C Pressure/temperature Sensor – G395- Incorrect Signal
-AND09 - Vehicle Electrical System Control Module – J519:
DTC 00256 - A/C Pressure/temperature Sensor – G395- No signal/communication

DTC Scenario 2

08 - Climate Control Module - J255:
DTC 00457 - Vehicle Electrical System Control Module – J519- Please check DTC memory
DTC 00256 - A/C Pressure/temperature Sensor – G395- Incorrect Signal
-AND09 - Vehicle Electrical System Control Module – J519:
DTC 01592 - Air Quality Sensor – G238- No signal/communication
DTC 00256 - A/C Pressure/temperature Sensor – G395- No signal/communication

Page 4 of 9
© 2012 Audi of America, Inc.
All rights reserved. Information contained in this document is based on the latest information available at the time of printing and is subject to the copyright and other intellectual property rights
of Audi of America, Inc., its affiliated companies and its licensors. All rights are reserved to make changes at any time without notice. No part of this document may be reproduced, stored in a
retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, nor may these materials be modified or reposted to other sites, without
the prior expressed written permission of the publisher.

Technical Service Bulletin
If scenario 1 is the case perform step 7.
If scenario 2 is the case perform steps 2 – 6.
Tip: The existing LIN cable connecting the J519 Vehicle Electrical System Control module to the G395
Pressure Sensor could be pinched or cut if scenario 2 is the case.
2. Check the LIN cable connecting the J519 Central Electrics Control unit to the G395 pressure sensor
according to guided fault finding.
3. Check the wire terminals in the connector at the G395 pressure sensor for proper attachment, possible
corrosion, and for any pins that may be pushed back or widened.
4. Check to make sure there is proper voltage going to the sensor and verify the ground is not intermittently open
(wiggle test).
5. Check the integrity of the wire
harness.
There are two known sections in
the wiring harness that can be
affected, but the potentially
affected areas are not limited to
these two known sections. One of
the known sections is in the
driver’ s footwell area where the
wire harness enters the interior of
the car from the engine bay
(Figure 1).

Figure 1. Wire harness in driver footwell area.

Page 5 of 9
© 2012 Audi of America, Inc.
All rights reserved. Information contained in this document is based on the latest information available at the time of printing and is subject to the copyright and other intellectual property rights
of Audi of America, Inc., its affiliated companies and its licensors. All rights are reserved to make changes at any time without notice. No part of this document may be reproduced, stored in a
retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, nor may these materials be modified or reposted to other sites, without
the prior expressed written permission of the publisher.

Technical Service Bulletin
The second known section is in
the wire harness located under
the driver’ s side headlight
(Figure 2).

Figure 2. Wire harness under driver’ s side headlight.
6. If a cut wire is found, install an overlay wire for the LIN bus signal. Do not attempt to repair the existing wire
harness.

a. Route the new LIN bus wire
from the power system control
unit J519 to the sender for
refrigerant
pressure/temperature G395 so
that it enters the interior of the
vehicle through the driver’ s
side fender/lower A-pillar area
through the grommet indicated
in Figures 3 and 5.
Tip: Do not route the wire
through the same opening

Figure 3. Grommet in driver’ s side fender/lower A-pillar area used for

used by the existing wire

pass-through for new overlay wire.

harness.
Tip: The LIN bus between J519 and G395 may contain a junction point shared with other modules
depending on the vehicle. Ensure to maintain the junction points when routing the overlay.

Page 6 of 9
© 2012 Audi of America, Inc.
All rights reserved. Information contained in this document is based on the latest information available at the time of printing and is subject to the copyright and other intellectual property rights
of Audi of America, Inc., its affiliated companies and its licensors. All rights are reserved to make changes at any time without notice. No part of this document may be reproduced, stored in a
retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, nor may these materials be modified or reposted to other sites, without
the prior expressed written permission of the publisher.

Technical Service Bulletin
On vehicles with a charisma
switch (ride selection switch
located on the instrument
panel) route the new cable of
the sender for refrigerant
pressure/temperature G395 to
junction B549 as indicated by
the red arrow in Figure 4.

Figure 4. Cable routing with charisma switch option.

Page 7 of 9
© 2012 Audi of America, Inc.
All rights reserved. Information contained in this document is based on the latest information available at the time of printing and is subject to the copyright and other intellectual property rights
of Audi of America, Inc., its affiliated companies and its licensors. All rights are reserved to make changes at any time without notice. No part of this document may be reproduced, stored in a
retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, nor may these materials be modified or reposted to other sites, without
the prior expressed written permission of the publisher.

Technical Service Bulletin
b. Seal off the opening around
the wire with Butyl sealant to
prevent water intrusion.

Figure 5. Seal off access hole in grommet with Butyl sealant.
7. Replace the sender for refrigerant pressure/temperature G395.

Warranty
Claim Type:

Use applicable claim type. If vehicle is outside any warranty, this Technical Service
Bulletin is informational only.

Service Number:

8709

Damage Code:

0010

Labor Operations:

Repair front left wiring loom

97 15 99 99

165 TU

Drain and refill refrigerant (if necessary)

87 03 17 00

50 TU

Check front left wiring loom

97 15 99 99

175 TU

Replace A/C Pressure/temperature Sensor –

Use appropriate

Use appropriate

G395-

published labor

published SRT in

operation in

ElsaWeb based

ElsaWeb based on on model.
model.

Page 8 of 9
© 2012 Audi of America, Inc.
All rights reserved. Information contained in this document is based on the latest information available at the time of printing and is subject to the copyright and other intellectual property rights
of Audi of America, Inc., its affiliated companies and its licensors. All rights are reserved to make changes at any time without notice. No part of this document may be reproduced, stored in a
retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, nor may these materials be modified or reposted to other sites, without
the prior expressed written permission of the publisher.

Technical Service Bulletin
Diagnostic Time:

GFF

01 50 00 00

Time stated on
diagnostic
protocol not to
exceed 50 TU.

Claim Comment:

Road test prior to service procedure

No allowance

0 TU

Road test after service procedure

No allowance

0 TU

As per TSB #2020124/8

All warranty claims submitted for payment must be in accordance with the Audi Warranty Policies and Procedures

Manual. Claims are subject to review or audit by Audi Warranty.

Required Parts and Tools
Part Number

Part Description

Quantity

4H0 959 126

Pressure sensor

1

Additional Information
All parts and service references provided in this TSB are subject to change and/or removal. Always check with
your Parts Department and service manuals for the latest information.

Page 9 of 9
© 2012 Audi of America, Inc.
All rights reserved. Information contained in this document is based on the latest information available at the time of printing and is subject to the copyright and other intellectual property rights
of Audi of America, Inc., its affiliated companies and its licensors. All rights are reserved to make changes at any time without notice. No part of this document may be reproduced, stored in a
retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, nor may these materials be modified or reposted to other sites, without
the prior expressed written permission of the publisher.