Code P0118 - previously P0117

Booya · Post by **Booya** » 20 Dec 2016, 03:27

I have a 97 850(non-turbo). She's been giving me fits for a couple of months now. She started by dying while I was out one day and refusing to start. I towed her home and she gave me codes for misfiring in cylinders 1,2,and 3. I checked compression and it was good in all 5 cylinders. A friend suggested to look at the cam position sensor so I did and the connector fell apart in my hand. I replaced the cam position sensor and all other codes went away except for the cam position sensor code! Since then, I have replace plugs, replaced the distributor cap and rotor, entire breather system. All the codes went away for about a week. Then P0117 popped up. So just to be on the safe side, I replaced the thermostat and temp sensor (all new parts) and even after clearing the code, it came back. My wife drove the car to work one morning and when she was going to come home it wouldn't start. I went to look at it and it started up for me but idled rough and now reads the code P0118. I drove her home and she seemed to run OK except at red lights when she would hitch and sputter randomly. Can anyone help? I'm afraid how much a mechanic is going to charge for whatever they want to make up when they look at her. Thanks.

Post by **abscate** » 20 Dec 2016, 04:14

Did you use Volvo for the temp sensor? ( it's often called ECT here) aftermarket works less than half the time. Inspect the connector and wires too. All your symptoms match a bad ECT

Booya · Post by **Booya** » 23 Dec 2016, 08:25

I will have to look at that. Thanks

Booya · Post by **Booya** » 09 Jan 2017, 11:01

How do I test the sensor to tell if it's bad or not?

Post by **abscate** » 09 Jan 2017, 13:31

Search this forum for the string

"Engine Coolant Temperature Resistance Chart"

and you will find the resistance numbers you can measure with a VOM if you/pal has one.

Otherwise, its a test by replacing.

DeathRex · Post by **DeathRex** » 09 Jan 2017, 16:55

Booya wrote: My wife drove the car to work one morning and when she was going to come home it wouldn't start. I went to look at it and it started up for me but idled rough and now reads the code P0118. I drove her home and she seemed to run OK except at red lights when she would hitch and sputter randomly.

Yea but how was the car running?

Booya · Post by **Booya** » 11 Jan 2017, 03:07

She seemed to run OK until I had to slow down or stop.

Post by **abscate** » 11 Jan 2017, 03:25

When you get the no start is when you can learn good information. Have some ether handy and give it a 1-2 second shot into the air intake, that's the fastest way to diagnose fuel vs ignition problem for running.

You have to use Volvo for that sensor though. After markets are a real roulette wheel spin.

dono · Post by **dono** » 19 Apr 2025, 12:00

Working on a 2004 XC70 156k mi 2.5T AWD

Chasing a P0118 code on the vehicle

I replaced thermostat with a genuine Volvo thermostat (including Volvo ECT sensor) and still get P0118.

- OBD II live data shows what appears to be correct coolant temp from cold to stable operating temp of ~185-190F ;
- radiator fan turns on high on cold startup and remains on.
- New ECT sensor resistance installed ohm meter reads ~11.9 at operating temp and ~28.2 cold/ambient temp.

I understand that P0118 "Engine Coolant Temperature Circuit High Input" likely indicates an open circuit. The connector looks highly suspect with crumbled plastic (yellow) that shattered and I had to blow out of Engine Coolant Temperature Sensor socket and 2mm bare wire showing in back (and very close together) so I have ordered a replacement connector. My questions are:

1. does this vehicle have two coolant temperature sensors and if so where is the sensor not at the thermostat?
2. where are the most common locations for Engine Coolant Temperature Sensor open circuit?

UPDATE: It was the connector. I did have to erase the code before the computer would believe the Engine Coolant Temperature Sensor was repaired...