It’s a long shot, but i am stumped. I have a 2003 gts 3.0l 5spd. Has a high idle. Have had the codes P0122 and P0107. I’ve cleaned throttle body and IAC. Replaced tps and mechanic let me know that the tps wires have power, but aren’t receiving signal from ecu when trying to program. Bad ecu or bad ground I’m assuming? Before i go and put a ton of money i need to make sure I’ve been trouble shooting correctly. Vehicle does run fine it just has an abnormally high idle around 1500-2000. Any help is appreciated.
TPS not receiving signal from ECU?
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If the grounds were possibly bad/damaged, the engine coolant temperature sensor and fuel differential pressure sensors would be affected too. They all share a common black wire according to the wiring diagram to a ground inside the ecu. I wouldn't necessarily count the ground connections being bad, but more than likely if you don't have problems with the two I listed, then the ground and connections can be assumed to be good.
You could double check that the signal is making it to the ecu by back-probing the pins and reading the voltage, but it could be difficult given where the ecu is located (passenger foot well, tucked behind the HVAC case. It is accessible without disassembling the dashboard/HVAC case).
Replacing the ecu requires that the keys be reprogrammed to the immobilizer and new ecu.
You could double check that the signal is making it to the ecu by back-probing the pins and reading the voltage, but it could be difficult given where the ecu is located (passenger foot well, tucked behind the HVAC case. It is accessible without disassembling the dashboard/HVAC case).
Replacing the ecu requires that the keys be reprogrammed to the immobilizer and new ecu.
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That's a TPS code and a MAP sensor code for low signal at the ECU. Both of these sensors are fed 5 volt power directly from the ECU, it's possible the 5V power supply in the ECU is fried but there are other components under the hood that use 5V power so it's more likely you have a broken wire junction under the hood.
Best thing to do would be find the 5V supply wire at the ECU under the dash and verify 5V is present there. If it is then you know you have a broken wire downstream, in the bay. It's a tedious task tracing wires like that but if your ECU isn't shot, replacing it won't fix it and that's a big, expensive job to do right.
Best thing to do would be find the 5V supply wire at the ECU under the dash and verify 5V is present there. If it is then you know you have a broken wire downstream, in the bay. It's a tedious task tracing wires like that but if your ECU isn't shot, replacing it won't fix it and that's a big, expensive job to do right.
I’ll have to trace the wiring for any cuts or chew marks. I did buy the car two months ago and it was in decent condition but so far this is the only issue I’ve ran into. Working on getting it wrapped and looking for some headers and other performance parts without breaking my bank account.
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12,506 Posts
Somebody probably cleaned the MAF. These units are not cleanable and it destroys them. Sounds like it shorted the 5V feed and that was enough to make the TPS and MAP sensors not work. Odd it didn't blow a fuse, but that's about the only way replacing the MAF could've fixed it.
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