Check Engine Light - What was your Problem?
#33
Need help. I have a '92 sc400 that is throwing a #25 code that I can't figure out. I changed fuel pump and filter already. Checked for vacuum leak between MAF and throttle body, no leak. Any thoughts of what it could be? Thinking I might have to reset codes and see if the check engine light comes back on.
#34
Maintenance Moderator
iTrader: (2)
Need help. I have a '92 sc400 that is throwing a #25 code that I can't figure out. I changed fuel pump and filter already. Checked for vacuum leak between MAF and throttle body, no leak. Any thoughts of what it could be? Thinking I might have to reset codes and see if the check engine light comes back on.
good chance you have fixed the car already, but without clearing the code, the ecu will not clear the light...
#35
Cleared the code last night and ran about 50 miles and the code came back. Just wanted to know what would be the next thing I should check? Would bad o2 sensors give a different code? Should I pull the injectors and manually clean them out or do a sea foam treatment?
#36
My light only seems to come on at idle and generally at a stop light when the engine is idling low in drive; then when I take off it generally will go off if not immediately; soon thereafter.
I guess I need to check the codes, but wondered if anyone has seen this and speculation on what it might be? I would think the light would come on and not go off, but it almost acts like it’s detecting a low oil pressure/voltage or something?
I guess I need to check the codes, but wondered if anyone has seen this and speculation on what it might be? I would think the light would come on and not go off, but it almost acts like it’s detecting a low oil pressure/voltage or something?
#37
Maintenance Moderator
iTrader: (2)
My light only seems to come on at idle and generally at a stop light when the engine is idling low in drive; then when I take off it generally will go off if not immediately; soon thereafter.
I guess I need to check the codes, but wondered if anyone has seen this and speculation on what it might be? I would think the light would come on and not go off, but it almost acts like it’s detecting a low oil pressure/voltage or something?
I guess I need to check the codes, but wondered if anyone has seen this and speculation on what it might be? I would think the light would come on and not go off, but it almost acts like it’s detecting a low oil pressure/voltage or something?
year make and model?
#38
Instructor
iTrader: (2)
Hey Cody (or anyone here)
Maybe you can help me.
I have a 95 SC400. Back in September I replaced both of the main O2 sensors. Since then I rarely drove my SC - probably only twice or three times a month - she stayed in the garage most of the time.
About 3 weeks ago, while driving, the CEL was back on. It was code 21 - main O2 sensor (left bank)
I was thinking I had bought a faulty O2 sensors - since I got both of them on ebay. They were Denso part # 234-4211.
Is it possible one of the new main O2 sensors has gone bad that early?
Also which one is the left bank main O2 sensor? Is it the driver side?
On Christmas eve, I warmed her up in the garage. After a few minutes idling, the engine died suddenly.
Checked the EFI fuse and I found the 30 amp fuse was blown. Replaced it and she fired up right away. The CEL was gone.
Turned her off and started again and then CEL went back on.
Now I have code 21, 27 & 28.
What gives? Please advise.
Thanks in advance.
PS: How long does it take to reset the CEL by pulling out the EFI fuse? Some say it has to be no less than 30 minutes. Is this right?
Maybe you can help me.
I have a 95 SC400. Back in September I replaced both of the main O2 sensors. Since then I rarely drove my SC - probably only twice or three times a month - she stayed in the garage most of the time.
About 3 weeks ago, while driving, the CEL was back on. It was code 21 - main O2 sensor (left bank)
I was thinking I had bought a faulty O2 sensors - since I got both of them on ebay. They were Denso part # 234-4211.
Is it possible one of the new main O2 sensors has gone bad that early?
Also which one is the left bank main O2 sensor? Is it the driver side?
On Christmas eve, I warmed her up in the garage. After a few minutes idling, the engine died suddenly.
Checked the EFI fuse and I found the 30 amp fuse was blown. Replaced it and she fired up right away. The CEL was gone.
Turned her off and started again and then CEL went back on.
Now I have code 21, 27 & 28.
What gives? Please advise.
Thanks in advance.
PS: How long does it take to reset the CEL by pulling out the EFI fuse? Some say it has to be no less than 30 minutes. Is this right?
Last edited by Maeve; 12-28-11 at 07:31 PM.
#39
Instructor
iTrader: (2)
Hey Cody (or anyone here)
Maybe you can help me.
I have a 95 SC400. Back in September I replaced both of the main O2 sensors. Since then I rarely drove my SC - probably only twice or three times a month - she stayed in the garage most of the time.
About 3 weeks ago, while driving, the CEL was back on. It was code 21 - main O2 sensor (left bank)
I was thinking I had bought a faulty O2 sensors - since I got both of them on ebay. They were Denso part # 234-4211.
Is it possible one of the new main O2 sensors has gone bad that early?
Also which one is the left bank main O2 sensor? Is it the driver side?
On Christmas eve, I warmed her up in the garage. After a few minutes idling, the engine died suddenly.
Checked the EFI fuse and I found the 30 amp fuse was blown. Replaced it and she fired up right away. The CEL was gone.
Turned her off and started again and then CEL went back on.
Now I have code 21, 27 & 28.
What gives? Please advise.
Thanks in advance.
PS: How long does it take to reset the CEL by pulling out the EFI fuse? Some say it has to be no less than 30 minutes. Is this right?
Maybe you can help me.
I have a 95 SC400. Back in September I replaced both of the main O2 sensors. Since then I rarely drove my SC - probably only twice or three times a month - she stayed in the garage most of the time.
About 3 weeks ago, while driving, the CEL was back on. It was code 21 - main O2 sensor (left bank)
I was thinking I had bought a faulty O2 sensors - since I got both of them on ebay. They were Denso part # 234-4211.
Is it possible one of the new main O2 sensors has gone bad that early?
Also which one is the left bank main O2 sensor? Is it the driver side?
On Christmas eve, I warmed her up in the garage. After a few minutes idling, the engine died suddenly.
Checked the EFI fuse and I found the 30 amp fuse was blown. Replaced it and she fired up right away. The CEL was gone.
Turned her off and started again and then CEL went back on.
Now I have code 21, 27 & 28.
What gives? Please advise.
Thanks in advance.
PS: How long does it take to reset the CEL by pulling out the EFI fuse? Some say it has to be no less than 30 minutes. Is this right?
I just bought another brand new Denso O2 sensors for both main sensors. Reset the CEL and it was good for a moment. After a short drive, these code 21, 27 & 28 showed up again. This just doesn't make any sense. I don't think the sub O2 sensors are also bad or are they?
Shut the engine off and re-started again, there was no more CEL. Took her for another 30 minutes drive and nothing happened - it was good - no more CEL. But then I stopped to get some fuel and after that the CEL was throwing the same codes (21, 27 & 28) again.
Now I'm leaning towards the bad ECU. Btw, my SC has 176,000 miles.
I will update later.
#40
Instructor
iTrader: (2)
Update:
I just bought another brand new Denso O2 sensors for both main sensors. Reset the CEL and it was good for a moment. After a short drive, these code 21, 27 & 28 showed up again. This just doesn't make any sense. I don't think the sub O2 sensors are also bad or are they?
Shut the engine off and re-started again, there was no more CEL. Took her for another 30 minutes drive and nothing happened - it was good - no more CEL. But then I stopped to get some fuel and after that the CEL was throwing the same codes (21, 27 & 28) again.
Now I'm leaning towards the bad ECU. Btw, my SC has 176,000 miles.
I will update later.
I just bought another brand new Denso O2 sensors for both main sensors. Reset the CEL and it was good for a moment. After a short drive, these code 21, 27 & 28 showed up again. This just doesn't make any sense. I don't think the sub O2 sensors are also bad or are they?
Shut the engine off and re-started again, there was no more CEL. Took her for another 30 minutes drive and nothing happened - it was good - no more CEL. But then I stopped to get some fuel and after that the CEL was throwing the same codes (21, 27 & 28) again.
Now I'm leaning towards the bad ECU. Btw, my SC has 176,000 miles.
I will update later.
I pulled out the engine ECU and this is what I found:
No wonder the 30amp ECU fuse was blown the other day, but then why is she still running?
I also think the previous owner installed a remanufactured engine ECU.
Anyone selling a 1995 Engine ECU? Let me know.
I also created a thread: [WTB] 1995 SC400 ECU (for CA specs only)
#42
I'm also getting a code 13 but it's intermittent. I checked the cam sensor wires on both sides, neither one was cut nor damaged. I'm going to check the sensors this weekend to see if they're still up to spec. Does anyone know what's the voltage spec for the sensors?
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