Trouble code P2185 ECT sensor 2

NICKAG

MEMBER
2007 HONDA FIT
0.5L
4 CYL
2WD
AUTOMATIC
85,000 MILES

Hi,
Replaced the ECT sensor at bottom of radiator. Harness wires were corroded off the the sensor connector, so rather than repair the entire harness, I spliced in a new section of wire and soldered back on to the connector. Thought for sure that was the problem. Tried to reset Engine Trouble light with handheld code reader but the light keeps coming on. Pretty sure the harness repair went well and new ECT sensor installed, but the same trouble code remains.
Now what? I do not know where to find diagnostic information to test continuity, resistance, or other data. Hate to take it to a dealer. Can anyone help?

7 Replies

KEN L

MASTER CERTIFIED MECHANIC
48,363 POSTS

Hello,

There are two coolant temperature sensors. The one you replaced is for the cooling fan. Here is a guide to help you step by step change the sensor and the location of the coolant sensor up by the upper radiator hose so you can see how its done on your car below:

https://www.2carpros.com/articles/coolant-temperature-sensor-cts-replacement

Check out the diagrams (below). Please let us know if you need anything else to get the problem fixed.

Cheers, Ken

Image (Click to make bigger)

SPONSORED LINKS

Was this

answer

helpful?

Yes

Saturday, October 13th, 2018 AT 1:45 PM

NICKAG

MEMBER
4 POSTS

Hi Ken, thanks for the reply. From what I understand, code P2185 refers to coolant sensor 2. When I saw the wire harness at the connector completely corroded to the point that it was no longer attached, I thought I found the problem. Since I could not locate a pigtail replacement connector and Honda wants $860 for a replacement harness, I carefully repaired the existing one by soldering a length of wire to the existing connector. So, I could try replacing the other ECT sensor (1) near the thermostat, but I have a feeling that the harness or repaired connector might be causing the check engine light issue. I would like to find where I would check for continuity or other tests (voltage/resistance) to rule out the harness as the problem.

Was this

answer

helpful?

Yes

Saturday, October 13th, 2018 AT 5:41 PM

KEN L

MASTER CERTIFIED MECHANIC
48,363 POSTS

Good idea, here is the cooling fan wiring diagrams and a guide to help you run the test:

https://www.2carpros.com/articles/how-to-check-wiring

Check out the diagrams (below). Please let us know what happens.

Cheers, Ken

Image (Click to make bigger)

Was this

answer

helpful?

Yes

Monday, October 15th, 2018 AT 10:25 AM

NICKAG

MEMBER
4 POSTS

Thanks for the diagrams, Ken,
I will see if I can figure this out and let you know how it goes,
Much appreciated,

Nick

Was this

answer

helpful?

Yes

Monday, October 15th, 2018 AT 12:20 PM

KEN L

MASTER CERTIFIED MECHANIC
48,363 POSTS

You are welcome let us know what happens.

SPONSORED LINKS

Was this

answer

helpful?

Yes

Tuesday, October 16th, 2018 AT 10:07 AM

NICKAG

MEMBER
4 POSTS

Hello Ken,
I spent four hours in a local boneyard and eureka! I found a wire harness in good shape and salvaged the connector plug along with about ten inches of the cable for the ECT2 sensor. After solder splicing it to the harness I cleared the trouble code and the check engine light did not come back on. Probably did not even need the new sensor, but that is okay, still a cheap fix. Thanks for all of your input!

Nick

Was this

answer

helpful?

Yes

Monday, October 22nd, 2018 AT 5:23 PM

KEN L