Had my check engine light come on last week took it to auto zone and it was PO128 and was told it was a bad thermostat. I replaced the thermostat ($150!) and the check engine light is still coming on. I reset it and everything, any ideas of what to try next?

 

$150 is way too much for buying a thermostat. Did you have the dealership do the work, or did you install it?

Is the engine overheating at all? Also, start the car and turn on the a/c. See if both fans for the radiator are working.

 

That included labor, I was told the thermostat was underneath the car in the Accord so I decided to have it done by a mechanic. I totally got ripped and I know it, but the thermostat cost $60 itself.

No overheating, the heater and the AC work fine. I will go out and check the fans in a bit. If they are both working what is the next option?

 

P0128 can be problems with the cooling system, ECT 1 sensor, ECT 2 sensor, or ECM/PCM. However, for your generation Accord, this usually had to do with the ECT 2 sensor. Check the connector to make sure there is no corrosion and it is tight. The sensor, connector or harness may need to be replaced. See this thread:

honda-tech.com/showthread.php?t=2461422

 

Ok, I went out and started my car with no fan running and neither fan were running. I turned on the heat and still no fan running, I turned on the AC and neither fan ran as well..Would this throw the PO128 code up though?

Redbull-Instead of chasing ghosts and spending more money what would be the best option to know for sure?

 

Is this a 4 cylinder or 6 cylinder?

Usually with the fans not running, fuses are checked first.

There actually are a lot of troubleshooting steps. Some you may not be able to do without the proper diagnostic tools. I am not sure yet if you can jump the ECT connector like the older Hondas to test if the fans come on.

I believe ECT sensor 1 is for the ignition and fuel data in the ECU and that ECT sensor 2 is for triggering the fans.

I believe the ECT 2 is located on the engine for the V6 and in the radiator for the I4.

 

It is a 4 cylinder.

 

I'll give some of the quick and easy checks for now. Also, do you live in an area with snow, etc.?

1. Check the No.9 (20 A ) and No.11 (20 A ) fuses in the under-hood fuse/relay box, and the No.30 (7.5 A ) fuse in the under-dash fuse/relay box.

2. Check the cleanliness and tightness of connector. For your I4, I believe the ECT sensor 2 is located at the bottom of the radiator. You may have a splash shield cover under it though. If you see corrosion on the connector or the electrical part of the sensor, this may be the cause of the problem.

 

Yes I do live in an area with snow. Have about 5 inches on the ground right now. I will check these steps out tomorrow any other tips toss them my way and I will check them.

 

I don't live in an area with snow; but, I heard and read a lot about problems with the ECT 2 sensor for those who live in areas of snow.

My gut feeling is that it is the ECT 2 sensor connector, wiring, or sensor or even all of them. There are people that had to replace the sensor and the harness connector to resolve the problem. It actually is not unheard of.