How To Proceed With Troubleshooting

WARNING: This page is about a different car, the 2002 Lexus SC 430. However, it is still accessible from the selected car via links, so may be relevant.

VEHICLE BROUGHT TO WORKSHOP
1. GO TO NEXT STEP
CUSTOMER PROBLEM ANALYSIS CHECK AND PROBLEM SYMPTOM CONFIRMATION
1. GO TO NEXT STEP
CRANK ENGINE FOR MORE THAN 10 SECONDS
1. GO TO NEXT STEP
CHECK DIAGNOSTICS TROUBLE CODE OF ECM, see DIAGNOSTIC TROUBLE CODE CHART .
1. Check that diagnostics trouble code B2799 does not output.
1. OK: DTC B2799, See DTC B2799: ENGINE IMMOBILIZER SYSTEM MALFUNCTION .
2. NG: GO TO NEXT STEP

CHECK LEXUS HAND-HELD TESTER

ECU DATA MONITOR
1. Make a judgement of good or bad and find out a malfunctioning part by the data monitor.
Standard:

IMMOBILIZER ECU (TRANSPONDER KEY COMPUTER ASSEMBLY) (SWITCH CONDITION)

SPECIFIED CONDITION

Item	Condition	Specified condition
KEY SW	IG ON-->WITHOUT KEY	ON/OFF

NG: GO TO KEY REMAINDER WARNING SYSTEM, see HOW TO PROCEED WITH TROUBLESHOOTING .
OK: GO TO NEXT STEP

CHECK DIAGNOSTICS TROUBLE CODE OF TRANSPONDER KEY ECU ASSEMBLY, see DIAGNOSTIC TROUBLE CODE CHART .
1. Check a DTC and note it if a code is output.
2. Delete the DTC.
3. Check if the DTC will be output once again, when the problem symptom is simulated based on the noted code.
  1. Without an output of the code, proceed to "A".
  2. With an output of the code, proceed to "B".
1. B: GO TO STEP 8
2. A: GO TO NEXT STEP
PROBLEM SYMPTOMS TABLE, see PROBLEM SYMPTOMS TABLE .
1. Without an applicable problem symptom table, proceed to "A".
2. With an applicable problem symptom table, proceed to "B".
1. B: GO TO STEP 8
2. A: GO TO NEXT STEP
ACCORDING TO PROBLEM SYMPTOM, PERFORM TROUBLESHOOTING
1. PRE-CHECK, See PRE-CHECK .
  1. Inspection with LEXUS hand-held tester (ECU data monitor)
  2. Inspection with LEXUS hand-held tester (Active test)
2. TERMINALS OF ECU
ADJUSTMENT, REPAIR OR REPLACE
1. GO TO NEXT STEP
2. END