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Unplugged Battery And Now It Wont Start


bchan

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So I went to change my deck out but my new deck didn't come in yet so I left the battery disconnected for 12+ hours. I wanted to check something on the AC so I reconnected my battery, but now it won't start and it makes a buzzing/humming noise from the TPS or the motor. I did change out the battery and it cranks but doesn't start. Thinking it was flooded, I pushed the gas pedal in the way down and tried but still no good. I then tried to reset the ecu (both by disconnecting the negative terminal and pulling fuses and tried them at the same time too) but that didn't work. So I then tried keeping the gas pedal down for 30 seconds with the car in the "ON" position and then tried again but still got nothing. I don't know if this makes a difference (since I didn't touch it) but there is about an inch or so of slack from the throttle cable that I can feed to the gas pedal.

I checked most of the fuses and made sure all the connections were solid and they seem to be fine. It was running just fine before I unplugged the battery so I was thinking that I did something by; 1. Disconnecting the battery, and 2. Leaving it disconnected for so long.

That's as much info as I can think of for now and I'll try to update as I do more looking into this. I have tried looking this up but can't find anything like this so if I missed something then my bad and could you link it? But thanks all for the help in advance!!

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Update:

I think I shorted something when I REconnected my battery to check the AC. When I checked the amprage coming from the fuse box with the car off and battery connected, the EFI fuse would read all over and the ECU B1 fuse reads between 55-56 mA consistently but starts off at 150+ mA. Also the alternator fuse was reading around 2 or so mA and about 1.7 mA to the radio that's not plugged in but I'm not sure if that was normal. I did also go buy a cheap OBD II reader (I noticed the MIL light turned on so I thought I should check it out) and it threw me a P1127. Looked that code up and I found out it was an open/short in my ECTS (but when I checked the apmrage at the fuse with the battery connected and car off, it read 0).

So I think my no start is because of a flooded engine due to the EFI and ECU drawing power with a battery connected and probably dripping gas in the cylinders. I also noticed that the whirring/humming can start before I try to turn the engine on by pushing the gas pedal but I don't think that the ECTS being open/shorted can cause a no start(?).

I was wondering if the open/short in the ECTS was in the ECU, the wiring harness itself, or both since when I push the gas pedal I can start the whirring/humming noise. I don't think the ECU is shorted because it threw the code so the open/short is in the harness itself and a power wire must have burned and fused the APS with the TPS since I can start the whirring/humming with the gas pedal (but can't stop it since the TPS would be grounded through the APS). If it is the harness, then why would the wires fail before the fuses? I thought that's what the fuses were for...

Any help/advice/confirmation would be much appreciated!!

P.S. if you guys were wondering, I wasn't paying attention when I reconnected my battery and I put the negative side on first then the positive side

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  • 8 years later...

What are the Possible Causes of the DTC P1127 Lexus? NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
Faulty Electronic Throttle Control System (ETCS)
Actuator Electronic Throttle Control System (ETCS)
Actuator harness is open or shorted Electronic Throttle Control System (ETCS)
Actuator circuit poor electrical connection


Read more: https://www.autocodes.com/p1127_lexus.html

It may be that locating the specific cause is not exactly simple for the doityourselfer. 

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