Lexus DTC B2796 User manual

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Page 1 of 3
Title:
TROUBLESHOOTING IMMOBILIZER
DTC B2796
Models:
’98 & ’99 All Models
TechnicalService
InformationBulletin
March 12, 1999
EL003–99
The Diagnostic Section (DI) of the Repair Manual has been expanded and clarified to
assist in troubleshooting the Engine Immobilizer System. Use this information in
accordance with the current Repair Manual for each model to diagnose the system.
S1998 and 1999 All Models
DTC B2796 No Communication In
Immobilizer System
CIRCUIT DESCRIPTION
This DTC is stored in memory when a key that does not have a Transponder Chip is
inserted into the ignition or if there is loss of communication between the key and ECM.
DTC No. Condition Probable Cause
B2796 SNo Communication
SKey
STransponder key coil
STransponder key amplifier
SWire harness
SECM
OP CODE DESCRIPTION TIME OPN T1 T2
N/A Not Applicable to Warranty – – – –
ELECTRICAL
Introduction
Affected
Vehicles
Diagnostic
Procedure
Warranty
Information

TROUBLESHOOTING IMMOBLIZER DTC B2796 – EL003-99 March 12, 1999
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Delete the DTC and insert all presently available keys to check
whether the engine starts or not.
1
RESULT:
(A) All keys start the engine.
(B) A specific key does not start the
engine. DTC (B2796) is stored in
memory.
(C) All keys do not start the engine.
DTC (B2796) is stored in memory.
NOTE:
If the result is “A”, seek additional
information from the customer to see if
he/she ever inserted a key without a
Transponder Chip into the ignition.
No Problem.
Replace the Transponder Key Coil.
The Transponder Chip of a specific
key is defective. Replace the key.
Check the Transponder Key Coil. Refer to the Transponder Key
Coil Inspection Procedure in the Repair Manual.
2
A
B
C
NG
OK
Diagnostic
Procedure

TROUBLESHOOTING IMMOBLIZER DTC B2796 – EL003-99 March 12, 1999
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Check the harness and connector between the Transponder Key
Amplifier and ECM.
3
Repair or replace the damaged
harness and/or connector.
Replace the Transponder Key
Amplifier.
Exchange the Transponder Key Amplifier with a known good one.
Does the system operate normally?
4
Replace the ECM.
NG
OK
YES
NO