OBD I codes

1992 LEXUS ES 300
198,000 MILES • 6 CYL • FWD • AUTOMATIC
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SLEDBOY2K
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I have a 1992 Lexus Es 300 (obd 1). My check engine light does not illuminate when ignition is first turned on. Tried pull codes manually and with a code reader but the only thing that happens is the O/D OFF light starts flashing. The check engine light never comes on at all. Car recently failed emissions. Why won't my check engine light illuminate, and why can't the code reader pull codes from the ecm?
Jan 8, 2011 at 12:27 AM
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KHLOW2008
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When the CEL does not turn on, it could be a fault with the wiring circuit, a bad bulb or a faulty ECM.

When scan tool cannot communicate with the ECM, it coudl be a faulty ECM, wiring fault, missing power supply or the scan tool is not compatible.

Remove the instrument cluster to check the CEL bulb. Test for continuity of wire between the Check Connector and TCCS ECU terminal B4, Green/Red wire.
Jan 8, 2011 at 5:01 PM
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