57 Instrument Cluster Message: "Engine/Power Unit Start System: Fault. Please Contact Workshop"; B143C29 (GROUP 57, NO. 25-82)

57 INSTRUMENT CLUSTER MESSAGE: "ENGINE/POWER UNIT START SYSTEM: FAULT. PLEASE CONTACT WORKSHOP"; B143C29

TECHNICAL SERVICE BULLETIN

SERVICE INFORMATION

57 25 82 2077631/1 April 16, 2025.

Model(s)	Year	VIN Range	Vehicle-Specific Equipment
A4, A4 allroad, and Q7	2017 - 2025	All	Not Applicable
S4, A5 Sportback, S5 Sportback, Q5, and SQ5	2018 - 2025
A5, A5 Cabriolet, S5, and S5 Cabriolet	2018 - 2024
RS 5	2018 - 2019 2021 - 2024
A6, A7, A8, and Q8	2019 - 2025
RS 5 Sportback	2019 2021 - 2025
e-tron	2019 2021 - 2023
A6 allroad, S6, S7, S8, Q5 e quattro, SQ7, SQ8, and RS Q8	2020 - 2025
e-tron Sportback	2020 - 2023
A8 e quattro	2020 - 2021
RS 6 Avant, RS 7, Q5 Sportback, and SQ5 Sportback	2021 - 2025
A7 e quattro	2021 - 2022
Q8 e-tron, Q8 Sportback e-tron, SQ8 e-tron, and SQ8 Sportback e-tron	2024 - 2025

CONDITION

Customer states: 

• The message "Power unit start system: fault. Please contact workshop" or "Engine start system: fault. Please contact workshop" appears in the instrument cluster.

Workshop findings: 

The Following DTC may be stored relating to the Comfort System Central Control Module, -J393- (address word 0046):

• B143C29  Access/Start Authorization Button, implausible signal - symptom number 65638  .

The ignition button is working correctly.

This TSB only applies in conjunction with the event memory entry AND symptom number 65638. 

TECHNICAL BACKGROUND 1

The DTC B143C29  Access/Start Authorization Button, implausible signal" with symptom number 65638  means that not all the positions of the button were detected when it was pressed 30 times in a row (from model year 2023: 50 times). The reason may be that the customer did not press the button all the way down.

PRODUCTION SOLUTION

From model year 2023: Threshold at which the event memory entry is logged increased to 50 presses.

SERVICE

In convenience system central control unit J393 (diagnostic address 0046), please check whether all three button positions are detected in the measured value "entry and start authorization button" when the button is pressed all the way down. 

If the DTC is logged statically and all button positions were detected, it should subsequently be intermittent.

If all button positions are detected, it can be assumed that the button is okay and that the complaint was caused by the button not being fully pressed down several times in a row. It is not necessary to replace the button.

Please inform the customer accordingly:

Please press the "START ENGINE STOP" button all the way down, as otherwise the message "Power unit start system: fault. Please contact workshop" or "Engine start system: fault. Please contact workshop" will be shown on the instrument cluster if the button is not pressed all the way down 30 times in a row (from model year 2023).

WARRANTY

Claim Type:	If the vehicle is outside of any warranty, this Technical Service Bulletin is informational only.
Service Number:	9677
Damage Code:	0040
Labor Operations:	GFF/Guided Functions	0150 0000	Time stated on the diagnostic protocol
	Charge Battery	2706 8950	See SRT with associated operations
	Replace start/stop button	9677 19xx/9677 55xx	See SRT with associated operations
Claim Comment:	As per TSB 2077631/1

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.

ADDITIONAL INFORMATION

All part and service references provided in this TSB (2077631  ) are subject to change and/or removal. Always check with your Parts Department and/or ETKA for the latest information and parts bulletins. Please check the Repair Manual for fasteners, bolts, nuts, and screws that require replacement during the repair.

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