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I have 96 Lexus es300, car ran fine prior to this. During driving it would briefly flash CEL light and once parked, next morning it died at start up. I still can start it but it dies within 5-10 seconds. I am not able to pull codes (says malfunction communicating)
I’ve checked fuses, various sensors, grounds. How do I check coolant temperature sensor? Can I do it right on the car or does it have to be in boiling water. I was not able to get a reading with my multimeter from coolant temp sensor. Also I’ve checked camshaft position sensor and it didn’t have a reading.
Thanks in advance.
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Check the battery, make sure it is strong, tight and has good, clean connections…
Then try to pull the codes again, if the same issue try a different scanner… If this is unsuccessful, then you may be looking at ECM related issues or a bad ECM..
Don’t be concerned with the CTS and Cam position sensor for the time being…
-Karl
You already have… By not getting any codes and having errors in connecting…. The old school way of testing was to get near the ECM and take a good sniff and see if you smell burnt toast….
It may be a fuse or wiring issue, but since you said you checked all the fuses that starts to eliminate things…
Has any recent work been done to this car… Anything at all?
-Karl
While the car is running for short 10 seconds or so it displays CEL, if only I could pull codes, that way I could have an idea of where to look at. Why would ECM just go out all of a sudden? I might try cleaning all the connections to ECM and see if that will improve it.
I was watching a video on youtube of a guy diagnosing similar problem on an Echo and it turned out to be a dirty engine ground by the thermostat housing. I cleaned all the grounds and it still does it.The more you can tell us the better…. Bad grounds can cause funny issues… Has there been any accident recently or has it been painted?
If you have a good strong battery and clean, tight connections and all the fuses/relays are good, then here are my suggestions:
1. Get another Scan tool to see if it can communicate… (if you have a Harbor Freight model, those have been shown to have issues from time to time)… That is why I say this.
2. Look behind your glove box and get near your ECM… Take a good strong whiff as close as possible to the ECM….(note, this is not the most accurate way to test, especially on newer models).
3. Call your local Pick n pull and see how much a used ECM costs, and the guarantee..
4. Here is where it gets funny, and I have to question your mechanical abilities, the best way to go forward is to test your ECU and the inputs with a multimeter… Usually only the factory manual has this information and usually on EBAY they are over $100… so I am assuming you will not go this route…
5. Call your favorite mechanic and have him look at it….. This may be pricey and I don’t know your financial situation….
6. You can throw a new/salvage ECM in it to try, but I always encourage diagnosis first….
Best of luck…
-Karl
Scan tool I’m using is one of the best ones, (I had cheap ebay $60 one that I sold and got this one) Actron CP9180. I even hooked it up to another car to check and it works.
I will have to check ECU connections, maybe there’s corrosion/condensation cause car is parked outside most of the time. I just found someone on ebay rebuilds these for $75, if it turns out to be a bad ECM.
If I get ECM from junk yard I would have to reprogram the key cause there’s security system (at least that;s what I’ve read in repair manual) you have to do this when installing new ECM. So I’d rather keep original ECM and get it fixed.
I do have access to FSM for camry, which is basically the same car.
Just took out ECM and cleaned connectors with electrical connector cleaner, they looked clean anyways. Took it apart and didn’t see any blown parts and didn’t smell burnt. Reinstalled ECM and it still won’t connect to scanner or run properly.
I would say there is a good chance you have a bad ECM. When apart did you check for leaking capacitors. If you find these are baf you are probably best to get it re built… check ebay for these services. This would get your ecm working right and you wouldnt have to have your ecm re programmed to your key(more money). That is if it has an immobilizer… Is your car a Canadian version?
Here is a good link about capacitor problems in other Lexuses.
Karl
Thanks, I was searching internet last night and came across this same link. Yeah, I found a seller on ebay who rebuilds these and sending out ECM tomorrow. Even though it all looked good I’m not that good with electronics so I will have a pro check it out.
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