Please tell me it’s not the ECU
03-15-23, 03:33 PM
#1
Intermediate
Thread Starter
Please tell me it’s not the ECU
Was having starting issues, jumped the car a few times and swapped batteries, ended up being a loose connection. Now the car starts right up but is having major electrical issues.
No climate fan, says something about AC connection. Fuel light is blinking, windows won’t work from drivers panel (they work from each individual door). Dome light works in the On position but not from Door. And probably other issues I haven’t found yet.
Was running fine last time I drove it, now has one pending misfire at idle and when I tried to idle up and down the street I got multiple misfire codes.
Checked every fuse I could. Unplugged the ECU and battery and let sit for 15min. Still having same issues.
2001 GS300
No climate fan, says something about AC connection. Fuel light is blinking, windows won’t work from drivers panel (they work from each individual door). Dome light works in the On position but not from Door. And probably other issues I haven’t found yet.
Was running fine last time I drove it, now has one pending misfire at idle and when I tried to idle up and down the street I got multiple misfire codes.
Checked every fuse I could. Unplugged the ECU and battery and let sit for 15min. Still having same issues.
2001 GS300
03-15-23, 03:54 PM
#3
Intermediate
Thread Starter
The P0305 comes up when idling, no check engine light but obviously running rough. When attempting to go up and down the street I basically got misfire codes on every cylinder, then the check engine light came on.
Rats were a thought (they live in the palm trees all around us) although I haven’t found any evidence of damage from them yet.
Rats were a thought (they live in the palm trees all around us) although I haven’t found any evidence of damage from them yet.
03-15-23, 05:09 PM
#4
Intermediate
Thread Starter
Pulling fuses over here… pulled the 7.5a OBD fuse from the drivers footwell and suddenly the dome light came on, checked the fan controls and it works. But now the VSC lights are on as well as the check engine light. I have a feeling this isn’t going to be cheap or easy.
03-15-23, 06:38 PM
#5
Intermediate
Thread Starter
Definitely have a short somewhere. Put the OBD fuse back in and suddenly nothing worked again, but the VSC lights stayed on.
Im thinking either water got in from the storms we’ve been having (although I didn’t see any signs of moisture), rodents (again, no signs yet), or ECU. This calls for someone that actually knows how to track and diagnose electrical issues.
Im thinking either water got in from the storms we’ve been having (although I didn’t see any signs of moisture), rodents (again, no signs yet), or ECU. This calls for someone that actually knows how to track and diagnose electrical issues.
03-16-23, 01:55 PM
#6
Intermediate
Thread Starter
Just in case anyone is following along…
Tried to start the car today and it was acting like the battery was dead (9.something volts, only clicking at the starter), so there’s a drain somewhere, which can be caused by a short. Pulled out the OBD fuse again and even though the battery was weak the car fired up.
Pulled the carpet back to check for moisture and everything is dry. Checked voltage coming into the OBD fuse and it’s a constant 12.5v. Checked voltage going out and it’s very erratic, jumping from high 10v to mid 12v.
If I’m correct this only sends a signal to the OBD port, which (again, IF I’m correct) is only maybe a foot away, two feet with extra wire. Let’s see what we find.
Edit: we found 500 miles of wire, why am I not surprised.
Tried to start the car today and it was acting like the battery was dead (9.something volts, only clicking at the starter), so there’s a drain somewhere, which can be caused by a short. Pulled out the OBD fuse again and even though the battery was weak the car fired up.
Pulled the carpet back to check for moisture and everything is dry. Checked voltage coming into the OBD fuse and it’s a constant 12.5v. Checked voltage going out and it’s very erratic, jumping from high 10v to mid 12v.
If I’m correct this only sends a signal to the OBD port, which (again, IF I’m correct) is only maybe a foot away, two feet with extra wire. Let’s see what we find.
Edit: we found 500 miles of wire, why am I not surprised.
Last edited by JaySco; 03-16-23 at 02:20 PM.
03-16-23, 03:33 PM
#8
Intermediate
Thread Starter
I’ve been going back and forth between the car and the internet (mostly archived ClubLexus posts). There have been many issues like mine, and coincidentally many of them come after heavy rain. Looks like most issues are resolved with BCM (body control module) #1 or #2, and in some cases the ECU. It’s still wet out here but I’m going to unplug everything and blow it all out, maybe let it sit for a day, and try again.
Oh, and when it stated today the VSC and check engine lights were out and it seemed to be idling smooth for the most part, so that’s reassuring.
03-17-23, 05:30 PM
#9
Intermediate
Thread Starter
Captains log, March 17th 2023.
Still hunting the elusive gremlin, we are slowly tracking its clues left behind.
So left the fuse out for a day and checked battery voltage, 12.3, perfect. That reinforces the finding that it’s whatever is downstream from that fuse location.
Also found moisture under the carpet on the right front footwell. Peeled it back and left the windows down to help air it out.
Still hunting the elusive gremlin, we are slowly tracking its clues left behind.
So left the fuse out for a day and checked battery voltage, 12.3, perfect. That reinforces the finding that it’s whatever is downstream from that fuse location.
Also found moisture under the carpet on the right front footwell. Peeled it back and left the windows down to help air it out.
03-17-23, 05:37 PM
#10
Lexus Champion
12.3 is low a healthy battery will maintain 12.6+ for weeks if there is no load.
03-17-23, 06:21 PM
#11
Intermediate
Thread Starter
Sorry, this was after i had had the doors open for a few minutes and cycled the key to ACC a couple times to test the function of some accessories. .3v loss should be acceptable, and much better than the 9v that was found yesterday.
03-17-23, 08:01 PM
#13
Intermediate
Thread Starter
Didn’t have time to find the source of the leak. Maybe this weekend.
Is behind the glovebox a common source of leaks?
Is behind the glovebox a common source of leaks?
Last edited by JaySco; 03-17-23 at 08:18 PM.