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Code P0118 on OBDII Reader

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mrblotto

mrblotto

Golden Member
The CEL on the Mother-In-Laws 2002 Oldsmobile Intrigue keeps coming on. She took it to a garage in PA (she's down visiting) and they said something about it being a 'coolant sensor'. This was the day before she came down. They said it's problably something electrical. They also mentioned it's probably not critical, so she can drive it, and they can fix it when she gets back.

I took my handy dandy OBDII reader and pulled the following. Bear with me 'cause I dont know what half of it means lol:
P0118 ---> MIL ON --> Monitrs --> 4 Inc --> Catalyst --> Evap --> SecAir --> EGR --> 5 Ready --> Misfire --> Fuel --> Comp --> O2 Snsr --> O2Htr

Now I loaded the OBDII software and it looks like a P0118 is an 'Engine Coolant Temp Circuit High Input'

Question: wtf is an 'Engine Coolant Temp Circuit High Input' and can the vehicle be driven for a little while before it's repaired?

I did clear the CEL as well. The MIL was like 'you can do that?' lmao

TIA oh AT gearheads!

Blah-Toe
 
replace thermostat

quick google on results :


  • A bad connection at the sensor
  • An open in the ground circuit between the ECT sensor and the PCM
  • A short in the voltage feed between the sensor and the PCM
  • A bad PCM (less likely)
  • A bad temperature sensor (shorted internally)
 
First thing is the current code, second one is just a flag saying the check engine light is on, because of that code. The rest you can ignore, its just telling you emissions monitor status. 5 monitors are reporting ready, the other 4 are incomplete because they don't start until the engine is at operating temp, which will never happen as far as the computer can tell because the coolant temp sensor is reporting incorrectly.

Check the voltage coming out of the coolant sensor and cross reference with the shop manual for what that voltage should be at a given temperature, replace sensor if out of range. Or just assume it's bad and replace the part if it's cheap enough, it's a 99% chance that it's bad anyway. (always a chance it's a bad connection in the connector or harness, or a cooling system issue)
 
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I'd say ECT too...it could also be bad wiring going to it. It's a cheap fix. On most cars you just ahve to lower the coolant a bit to replace.
 
Thank you so much for the info guys. That ECT looks just like a little tiny brass piece. And changing out a thermostat shouldn't be too difficult. Total cost for the parts would be like $30 I reckon.

Thanx again!
 
Can I hijack this for an obd code question?

I have a P0442 small evap leak that throws the cel for a few days or a week or so then goes away for a few months, been doing this for years, and its not the gas cap 🙂

2000 crown vic p71
 
google shows some were affected by a leak in either the fuel filler neck or tank itself. Earlier models may have a spider's nest in the Evap Canister system.

0442 is a very small leak so probably not visible.

I know you are saying it's not the cap, but if you haven't physically replaced it do that first. Not saying you didn't but many that have had this problem thought their cap 'looked' and 'clicked' fine so it wasn't an issue.

These aren't fun for a shadetree to hunt down, usually you need a vacuum setup to detect where the leak is.
 
^ Cap may click fine, but the o ring inside it can still be cracked or rotted, look closely. Otherwise, there are alot of plastic barbs and rubber vacuum hoses in the evap system allowing numerous opportunities for a small leak.
 
the cap was tested at emmissions several times and I recently replaced it just to be sure, the light came on a few days after i replaced it.

I have been ignoring it for years but this year it came on when I needed to get emmissions inspection done, I cleared the code by pulling the battery cable and oops, failed emmissions because systems werent ready, had to go drive for an hour and re-test the next day, luckily the light didnt come back on.
 
The MIL is gonna wait till she gets back to PA ( a few days)to have it repaired. My brother-in-law is a phenomenal mechanic/welder/fabricator/restorer and should have no trouble replacing the ECT and thermostat.

Thanx again AT!
 
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