Has this ever happened to anybody? Went to check the error codes using a wire in Te1 and E1, tranny in neutral - but it just keeps flashing. No pause at all. I've done this before when I had a problem with my ECU (which was replaced) and it worked, just gave me the wrong code (transmission speed sensor when it was really the ECU).

I've tried it on both the engine compartment port and TDCL diagnostic port underneath the steering wheel.

Weird, huh?

 

very strange. was the engine off and the key turned to acc?

 

Thanks for replying. ACC because you can't put tranny in neutral with it in OFF position. But yes, the engine wasn't running. ACC then ON to read the codes.

It just keeps flashing w/out any pause.

 

That means there are no codes set.

 

Thanks, Dicer. Does that mean there are no errors as far as the diagnostic is concerned?

If that's the case I guess I had better pull the ECU to see if some of the caps are leaking....dang, it's only about one year old.

 

i assume this is a 1st gen 90-94 car. what made you check for the code, was there was a light to begin with?

please inform me, why does the trans have to be in neutral? are you checking for tranny codes? try this procedure in park instead.

 

94 Lexus LS400. Having an issue w/ this vehicle (rough idle, shakes when accelerating at certain speeds and up hills) and have already changed the coils and cleaned throttle body, checked throttle position sensor, etc.

That's my understanding of how you check the codes, in neutral, I've done it before, see link below. And no, I'm checking for engine codes.

How to Read & Clear Diagnostic Trouble Codes 1990-1994 Lexus LS400

Thanks!

 

You probably have a spark plug, wires, coil, cap rotor issue. Maybe even a vacuum leak. The ECU is likely okay.
No pauses means no codes.

 

I'm just asking this for academic purposes but could it be an issue with the transmission or rear diff? Going uphill is harder on those components as well as the engine...isn't it?

 

lol no. not related to either of those.

consistent flashing with no breaks or pauses means there are no codes stored in the ECU. You either have a spark, fuel, or timing issue. If you just did any service, make sure you didn't screw it up, ala 180* flipped rotors or mismatched timing marks on the belt.

 

The alternator I think is bad. Not sure that's causing all the problems. I'll revert after I change it so that others, who might be having similar problems, can benefit. Thanks to everybody who has responded!

 

ahh, for some reason I thought the CEL would only blink when the engines running to verify the timing, but I see that's not the case

 

Yah, it's a good thing to know in case you ever run into issues. Things like these forums and the tutorials on http://www.lexls.com/ are such a huge help!

 

Finally solved my issue. It was a bad alternator. Replaced it with a remanu ALT I bought on eBay but then had the same problem, and knew it wasn't the battery as I had it tested. That ALT was bad from the start, poor packing, using only styrofoam peanuts and NO paper and just crappy USPS flimsy priority box.

Sent that back and bought one locally at an O'Reilly's but when I went to take off the ALT aforementioned from eBay the ALT plug (aka pigtail) disintegrated and had to order that off eBay as well cause I dang sure wasn't gonna order one from a dealer for 5X the price.

If you have to change your ALT you might wanna take a look at the pigtail, it might be in same condition as mine. That's a 21-year-old cheap plastic part that's faced some 100+º F (once 118º F) summers plus some cold winters, kind of surprised it lasted that long.

While searching for the wire config I saw these plugs (pigtails) for 40~60 cents a piece on Alibaba. Of course you probably have to buy a m/m of 100 pcs.

Fotos of the ALT pigtail:



Alternator pigtail 1





Alternator pigtail 2

 

I wonder if that connector was the root cause?