1993 ES300 ECM Programming

Old 08-01-2011, 01:26 PM
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Location: Austin, TX
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Smile 1993 ES300 ECM Programming


I purchased a 93 ES300 from a wrecker with known fuel system issues. I've verified the EFI fuses, Circuit Operation Relay, SFI Main Relay, and Fuel Pump itself all work and test out per service manual instructions; however, the fuel pump is still not kicking fuel up to the engine when cranked. I started testing the ECM and found the +B and +B1 don't show the expected 10-14V in reference to chassis ground so I tested for opens in the wiring between the COR and chassis ground and for opens in the wiring between the IGN fuse and COR. I also tested for opens between ECM and chassis ground. All of that checks out but the service manual says to go back to step one, checking the voltage between +B and +B1 to ground. So I'm stuck and have two questions:

1) Has anyone experienced this and has any additional suggestions?
2) I know of a salvage ECM I can go grab from a scrap yard, but programming I'm concerned with. Does the ECM have to be programmed to operate due to theft or security or will my odometer just be wrong?

Last edited by prat1293; 08-01-2011 at 01:27 PM. Reason: typos
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