No. 47-24

Symptom-based workshop manual
Service
47/24
ENU
2804
2
Warning Message “Ignition Lock Faulty - Service Required” in the Instrument Cluster / Fault
Memory Entry “B143C29” in the Rear-End Electronics Control Unit (SY 47/24)
Model Line:
911 (992)
Model Year:
As of 2020
Concerns:
Ignition starter switch
Symptom:
The white warning message “Ignition lock faulty - service required” is displayed in the
instrument cluster during the engine start-up process. The following fault memory entry is
stored in the fault memory of the rear-end electronics control unit:
•
Cause:
B143C29 - Ignition starter switch, signal implausible (010066)
When the ignition starter switch is actuated, the engine is started through the system from the moment
when the ignition starter switch is between switch position -1- (ignition on) and switch position -2- (engine
start)  Ignition starter switch position -Arrow-.
If the ignition starter switch for the engine start is not fully turned to the “Start engine” switch position
 Ignition starter switch position -2- but is released directly after engine start instead, therefore,
thereby switching back to the “Ignition on” switch position  Ignition starter switch position -1-, the
above-mentioned symptom occurs after the fifth consecutive incomplete start process.
Ignition starter switch position
AfterSales
Apr 9, 2024
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Service
2804
ENU
47/24
Symptom-based workshop manual
1
– Switch position “Ignition on”
2
– Switch position “Start engine”
Arrow – Engine start begins
Circle – Engine start release by “pushing brake” at ignition starter switch position  Ignition starter switch position
-ArrowInformation
The ignition starter switch is a redundant system with four signals to ensure proper operation even if
one of the signals is faulty. The signals are diagnosed by the rear-end electronics control unit at each
complete cycle (vehicle off until engine running). If the ignition starter switch is not fully actuated to start
the engine, one of the four signals is not switched. Due to the design of the redundant system, the engine
can still be started, but a fault memory entry is generated in the diagnostic system by the repeated
absence of the signal.
Information
After two full start-ups (“Start engine” switch position is reached completely), the warning message in the
instrument cluster automatically disappears; the fault memory entry “B143C29” remains “Passive” in the
rear-end electronics control unit.
Remedial
Action:
Inform the customer to turn the ignition starter switch to the “Start engine”  Ignition starter switch
position -2- switch position each time in order to start the engine so that the system will work as
intended.
Delete fault memory entry “B143C29 - Ignition starter switch, signal implausible (010066)” in the
rear-end electronics control unit.
Information
This complaint does not involve a defect of the ignition starter switch. As a result, this action cannot be
invoiced via a warranty claim.
Replacing the ignition starter switch will not correct the problem in this complaint and will not provide any
remedy.
Important Notice: Technical Bulletins issued by Porsche Cars North America, Inc. are intended only for use by professional automotive technicians who have attended Porsche service training
courses. They are written to inform those technicians of conditions that may occur on some Porsche vehicles, or to provide information that could assist in the proper servicing of a vehicle. Porsche special
tools may be necessary in order to perform certain operations identified in these bulletins. Use of tools and procedures other than those Porsche recommends in these bulletins may be detrimental to the
safe operation of your vehicle, and may endanger the people working on it. Properly trained Porsche technicians have the equipment, tools, safety instructions, and know-how to do the job properly and
safely. Part numbers listed in these bulletins are for reference only. The work procedures updated electronically in the Porsche PIWIS diagnostic and testing device take precedence and, in the event of a
discrepancy, the work procedures in the PIWIS Tester are the ones that must be followed.
© 2024 Porsche Cars North America, Inc.
Apr 9, 2024
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