Check Engine Light Mystery

pipesndrums

pipesndrums

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Joined
Aug 4, 2020
Messages
22
Location
McKinney TX
Hello folks,

Looking to see if anyone else has seen this. Here is the backstory, 2005 TJ running fine and did not have any check engine light on, all good.

Monday night we had this crazy rainstorm came through town, lot of rain and lightning overnight and the Jeep was outside on the driveway. The driveway is on a slope, Jeep was parked with the front lower than the backend. All starts up, I drive to work seems all good, gas-light comes on and I make a mental note to get gas.

Driving home, the gas-light is on and now the check engine light is on. Oh-oh. All gauges seem fine and I am close to home so I check the OBD and it says I got an issue. First error was Warning: vehicle battery has low voltage so I figured maybe need a new battery. Then next day error is HO2S heater control circuit low bank 1 sensor 1. I fill up on gas, and then the OBD says HO2S heater control circuit low bank 1 sensor 1, HO2S heater control circuit low bank 1 sensor 2, HO2S heater control circuit low bank 2 sensor 1 and HO2S heater control circuit low bank 2 sensor 2. Aghhh.

And then last night I am driving home, and the engine light goes off. All by itself. I did not clear any codes. Well that was weird.

Was wondering if maybe the rainstorm somehow caused all these things to happen and now it is dried out?
 
The codes may be stored still. It sounds like you have a reader, if not go to an auto parts chain and ask them to read them. They can also load test your battery; make sure the connections are clean and tight. Have you ever replaced the O2 sensors? They are a wear item.

Also, 05-06 PCMs can have issues (complaints but no recalls), so if you get stuck contact @Wranglerfix
 
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Water could have dripped onto the two harness connectors at upper center of the firewall. Disconnect and check for greenish/grayish oxidation on the individual terminals.
Disconnect and check the four 32 pin harness connectors that attach to the PCM for grayish or greenish oxidation on the individual terminals.
 
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Reactions: Jerry Bransford
RMETeeJay said:
The codes may be stored still. It sounds like you have a reader, if not go to an auto parts chain and ask them to read them. They can also load test your battery; make sure the connections are clean and tight. Have you ever replaced the O2 sensors? They are a wear item.

Also, 05-06 PCMs can have issues (complaints but no recalls), so if you get stuck contact @Wranglerfix
Click to expand...
Thanks, good suggestions. I will get them checked out. I have not replaced the O2 sensors but the previous owner might have, Just weird to me the check engine light is now off, I was expecting it to stay on until the codes were cleared but it's off now like nothing ever happened!
 
Stockli said:
Have you checked your grounds? Worth a look
Click to expand...
I will check and see, thanks good suggestion. When I changed out the vacuum line a while back I hsd to remove the battery and the contacts had a lot of buildup/corrosion on them that I cleaned up. Just weird how this came on suddenly and then now it's acting like nothing happened :)
 
CharlesHS said:
Water could have dripped onto the two harness connectors at upper center of the firewall. Disconnect and check for greenish/grayish oxidation on the individual terminals.
Disconnect and check the four 32 pin harness connectors that attach to the PCM for grayish or greenish oxidation on the individual terminals.
Click to expand...
Sounds good, will do! Thank you sir
 
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