TT011905

Technical Tip
01-19-05TT Engine Crank, No Start or No -J623- ECM Communication with
DTC U0100 Stored in ECM Fault Memory
Transaction No:
2054867/3
Release date:
09/5/2019
Condition
ATTENTION:
THIS IS A TECH TIP, NOT A TECHNICAL BULLETIN.
TECH TIPS ARE NOT ASSOCIATED WITH WARRANTY CLAIMING.
Applicable Vehicles
Model(s)
Year
Eng. Code
Trans. Code
VIN Range From
VIN Range To
Arteon, Atlas,
Jetta,Golf,
GTI,
Sportwagen,
Beetle, Beetle
Convertible,
Passat,
Tiguan, Tiguan
LWB
20182019
All
All
All
All
Revision Table
Instance Number
Published Date
Version Number
Reason For Update
2054867/3
9/5/19
01-19-05TT
Update effected vehicles
2054867/2
4/29/19
01-19-05TT
Add figures 1 and 2.
2054867/1
4/26/19
01-19-05TT
Original publication.
Technical Background
DTC
U0100
Description
Lost Communication with ECM/PCM
When disconnecting the Battery during service, the -J623- (ECM) may become internally shorted as a result of the
Positive Battery Terminal grounding out on the ECM case. DTC U0100 may set, as well as an engine crank with no
start condition.
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Technical Tip
01-19-05TT Engine Crank, No Start or No -J623- ECM Communication with
DTC U0100 Stored in ECM Fault Memory
Transaction No:
2054867/3
Release date:
09/5/2019
Service
When disconnecting or replacing a Battery, the Repair Manual procedure outlined in Elsa must be followed in its
entirety. See Repair Manual Group 27. The Battery Ground Cable must always be disconnected prior to the Battery
Positive Cable. Failure to do so may result in internal ECM damage
Figure 1
Figure 2
.
Additional Information
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the latest information available at the time of printing and is subject to the copyright and other intellectual property
rights of Volkswagen Group 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.
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