Changed out capacitors; how do I reset ECU
#1
Rookie
Thread Starter
Changed out capacitors; how do I reset ECU
Alright, at first I had no check engine light; however I do
have a strange light on the lower right hand bottom of my instrument cluster that I
have never before seen illuminated. It is a circle with a few dashes also circular around the sides; I do not know what the heck it indicates. I looked in the owner's manual and it states "take your vehicle to the dealer." Sorry manual but that is the one thing I will not do. If I did I wouldn't have food on the table!
Here is what happened susequent to reinstalling the ECU:
"Check Engine" light remained off for the first 1/2 hour of operation after ECU cap surgery. Then the check engine light came back on. The strange circle of light with a few perimeter dashes of light around the solid circle of light was their for the first time ever immediately after bringing the car back to life.
When I put my instrument cluster back in, after changing the caps in it, the airbag light had to be reset; I finally got around to doing that yesterday.
Now, I know my ECU is working great because I just took the car on a 330 mile road trip from
Seattle to Vancouver and back and it is getting well over 20MPG, and no hunt for idle, phenomenal response on acceleration, especially for a vehicle with 251K. I.e., all the issues that were present before the cap surgery have vanished.
I am thinking that, the airbag had to be reset, maybe there is a similar reset for the ECU that needs to be done. Something beyond merely taking out the ECU fuse; something beyond merely disconnecting the negative battery cable.
Can someone help me out here please? Thank you!
have a strange light on the lower right hand bottom of my instrument cluster that I
have never before seen illuminated. It is a circle with a few dashes also circular around the sides; I do not know what the heck it indicates. I looked in the owner's manual and it states "take your vehicle to the dealer." Sorry manual but that is the one thing I will not do. If I did I wouldn't have food on the table!
Here is what happened susequent to reinstalling the ECU:
"Check Engine" light remained off for the first 1/2 hour of operation after ECU cap surgery. Then the check engine light came back on. The strange circle of light with a few perimeter dashes of light around the solid circle of light was their for the first time ever immediately after bringing the car back to life.
When I put my instrument cluster back in, after changing the caps in it, the airbag light had to be reset; I finally got around to doing that yesterday.
Now, I know my ECU is working great because I just took the car on a 330 mile road trip from
Seattle to Vancouver and back and it is getting well over 20MPG, and no hunt for idle, phenomenal response on acceleration, especially for a vehicle with 251K. I.e., all the issues that were present before the cap surgery have vanished.
I am thinking that, the airbag had to be reset, maybe there is a similar reset for the ECU that needs to be done. Something beyond merely taking out the ECU fuse; something beyond merely disconnecting the negative battery cable.
Can someone help me out here please? Thank you!
#3
Lexus Test Driver
iTrader: (3)
If you are talking about a red circle with 3 marks on either side around it, like this:
Then that is the brake pad wear sensor. Just have a look and see if your pads need replacing or the sensor wire is broken.
When I did my coilovers and brakes, one of my sensors(front) was cut and taped off while the other(rear) was starting to fall apart. I fixed the rear so it still worked as it should and cleaned up the hack-job on the front but sure enough I must have jostled something as my light came on shortly after. I'm going to go back and clip both then redo both just to be sure before I order new sensors
As for the CEL, pull the code and see what it says.
Could be something completely unrelated and just coincidence that it popped up now or even something that was there before, just getting masked by the bad cap issue. If the caps were causing an issue that kept accurate but WRONG data from getting to the ECU, and/or the ECU interpreted that data received as correct because of the cap issue, then fixing the cap issue results in the accurate wrong data triggering a CEL. I have seen a few cases where a car came in with a faulty ECU, and NO CEL or codes for anything but a faulty ECU. Replaced the ECU and codes popped up for other systems that were cross-integrated into that sector of the ECU that was causing the issues. Tested those system and sure enough the parts were out of range/worn/broken, plugged in the old ECU and CEL's went away... data for those systems was not correct but still was in range according to that ECU.
So pull the code and see and go from there.
Then that is the brake pad wear sensor. Just have a look and see if your pads need replacing or the sensor wire is broken.
When I did my coilovers and brakes, one of my sensors(front) was cut and taped off while the other(rear) was starting to fall apart. I fixed the rear so it still worked as it should and cleaned up the hack-job on the front but sure enough I must have jostled something as my light came on shortly after. I'm going to go back and clip both then redo both just to be sure before I order new sensors
As for the CEL, pull the code and see what it says.
Could be something completely unrelated and just coincidence that it popped up now or even something that was there before, just getting masked by the bad cap issue. If the caps were causing an issue that kept accurate but WRONG data from getting to the ECU, and/or the ECU interpreted that data received as correct because of the cap issue, then fixing the cap issue results in the accurate wrong data triggering a CEL. I have seen a few cases where a car came in with a faulty ECU, and NO CEL or codes for anything but a faulty ECU. Replaced the ECU and codes popped up for other systems that were cross-integrated into that sector of the ECU that was causing the issues. Tested those system and sure enough the parts were out of range/worn/broken, plugged in the old ECU and CEL's went away... data for those systems was not correct but still was in range according to that ECU.
So pull the code and see and go from there.
#4
Rookie
Thread Starter
Thanks PureDrifter and Shmee.
That makes perfect sense because I just replaced both front pads and both front rotors with
slotted and drilled ones. One of the sensors had a broken wire and since I already had the
soldering iron out I tried to resolder it. I checked it with an ohm meter and it seemed okay.
Now that the ECU is working it is probably picking up on rear pads being worn. Those need
changing too! I am pretty sure I got that front one in okay. If I can do caps in an ECU and in
instrument cluster with success I figured I could handle a broken sensor wire.
Anway, thanks for telling me what the indiccator light is; now I CAN search!
That makes perfect sense because I just replaced both front pads and both front rotors with
slotted and drilled ones. One of the sensors had a broken wire and since I already had the
soldering iron out I tried to resolder it. I checked it with an ohm meter and it seemed okay.
Now that the ECU is working it is probably picking up on rear pads being worn. Those need
changing too! I am pretty sure I got that front one in okay. If I can do caps in an ECU and in
instrument cluster with success I figured I could handle a broken sensor wire.
Anway, thanks for telling me what the indiccator light is; now I CAN search!
#5
Lexus Champion
If I can do caps in an ECU and in instrument cluster with success I figured I could handle a broken sensor wire.
Now is the time to get back in there and get the right capacitors in there, before the lower glove box is back in!
You can post up which caps you are thinking of using and we will verify that they are low ESR!
#6
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Join Date: Dec 2012
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There is nothing like a charged out capacitor. A capacitor charges and discharges, you can’t reset by discharging a capacitor. Please rephrase the question using correct electronic terminology.
pcb fabrication
pcb fabrication
Last edited by georgesta; 04-01-15 at 02:30 PM.
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