Anyone...this is just before the OBD standard.

 

Lexus Codes

steviej

 

If you have a 94 or newer ES, the old OBD TE1 to E1 method doesn't work. 1MZ-FE's since inception in 1994 have been OBDII compliant. The first ever production engine to ever make that standard. The only ES to qualify are the ES250 90-91 2VZ-FE and ES300 92-93 3VZ-FE

 

beab951, I edited the title of your thread for better clarity

 

I even went to the local Toyota dealer and they were not able to read the code. I get a check engine light for a time and then it clears. The car runs great so I want to understand what the ECU thinks is wrong and the Lexus dealer is over 1.5 hours from my location. The connector is the same as the Camry, but the jumper used to start the code readout on the Camry doesn’t work on the 95 ES300 Lexus. They must have change the code in the ECU but why they would do this is beyond me.

 

I think I know what your CEL is coming on for. Usually CEL's pop up do to emissions reasons. I know of two main culprits. 1) O2 sensor is about to go or 2) the EGR Modulator Valve is about to go out or is in need of replacement. The EGR modulator valve is the curcular thing with a Denso sticker on it with vacuum lines running to and from the EGR and etc. That piece is a $70 item. I've had to replace this same piece on my old 95 Avalon 1MZ-FE V6. I would constantly reset the light...and the light would go back on after 100 miles or so. That's weird, the OBDII reader for the Camry should work for the ES. Same pinouts and etc.

 

Thanks for the input. For $70 I will just replace the unit. I was considering replacing the O2 sensor until I found that there were three of them and they cost over $100 each. I also don't think the O2 sensor is the problem since the light comes on soon after a cold start. The O2 sensor has to warm up to work so the timeline doesn't match.

 

Sounds like an EGR problem OR an intake MAF sensor problem. Make sure your wiring harness is firmly attatched to your MAF sensor on your intake.

 

Problem solved.

I purchased the Mitchell OnDemand Repair CD for the Lexus. After some reading, the 95 ES300 has three Data Link ports. DLC1 is in the passenger side of the engine compartment, DLC2 is a circular connector under the dash and DLC3 is in the Fuse Box. The DLC3 port IS the OBD2 connection port, it is on the right side of the fuse box. After reading the code I found I had a defective part in the transmission that was causing the check engine light to come on. I replace the Direct Clutch Speed sensor on the top of the trany and no more problems.

The 95 ES300 does support the OBD2 standard and the connector is inside the fuse box (inside the car) on the right side.