Help! - Insufficient ECT for Stable Operation

[surfbeetle]

The Service Engine Soon light came on in my Suburban last week. Not having a code reader handy, I reset the code by disconnecting the batteries to see if the light would reset. It stayed off for a couple of days and then the light came back on. I borrowed my cousin's code reader and "P0126, Insufficient Engine Coolant Temperature for Statble Operation" was the code that came up.

Any ideas on what this is or what I need to do to fix it? I was thinking that it is probably just a coolant sensor but I don't know where to find it. Thanks in advance for your input.

[Hubert]

Sensor or a stuck open thermostat. I had a stuck thermostat once. The computer expects a min coolant temp within x minutes of start up or will throw a code. You should get it fixed diesels like to run warm. The ECM makes adjustments according to ECT and various other sensors.

[surfbeetle]

Thanks for the reply. I called the local dealer and the service guy said that its around 300 to change the thermostats and about 200 for the sensor. Is there a way to pinpoint whether its the sensor or a stuck thermostat? The temp guage in the dash reads normally.

The weather around here just started to get cooler, instead of a normal 70 high and 50 low, its now getting down to 30 at night and 60 in the day. So I wonder if its got a stuck thermostat and not warming up quick enough.

[JohnC]

I called the local dealer and the service guy said that its around 300 to change the thermostats and about 200 for the sensor.

Go somewhere else! That's highway robbery!

If the dash gauge reads normally, and indicates the engine reaches normal temperature in a reasonable amount of time, the t-stats are probably OK. The PCM uses a different sensor for ECT than the gauge.

[chrisk1500]

Thanks for the reply. I called the local dealer and the service guy said that its around 300 to change the thermostats and about 200 for the sensor. Is there a way to pinpoint whether its the sensor or a stuck thermostat? The temp guage in the dash reads normally.

The weather around here just started to get cooler, instead of a normal 70 high and 50 low, its now getting down to 30 at night and 60 in the day. So I wonder if its got a stuck thermostat and not warming up quick enough.

Wow....$200 to change a sensor....I changed my CTS last week and it cost $30 for the sensor and $10 for the antifreeze that I spilled......the ECT is located in the coolant crossover tube...

[moondoggie]

Good Day!

My local NAPA will let me use their code reader on their parking lot (I've been buying parts from them for a long time), or I or anyone can "purchase" the code reader, get the codes, then return it for its full price. It's a loaner program that protects them from someone simply not bringing it back.

I'd be there's a parts store somewhere close by that will let you read the codes. If they'll let you borrow it on their lot, just drive around until your gauge shows full, normal operating temp (190F or so), then stop by & read what the PCM thinks your coolant temp is. As stated above, the gauge uses one sensor, the PCM another.

Good Luck & Blessings!

[surfbeetle]

Thanks for all of the advice. I currently have a snapon code reader I borrowed from my cousin. So I will see if it lets me read what the ecu thinks the temp is. Yes, the engine warms up in a normal amount of time and all seems to be okay. I think that I will start with the ECT sensor because yesterday, my wife told me that the SES light has now turned itself off.

Another forum related question: I started this thread and then turned on the email notifications in my control panel afterwards but I still don't get notified on replies to this thread. Does the email notification work?