Intermittently shutting down and low coolant warning

[Signature620]

Connect a known good sensor and submerge the probe of it in some water. Do Peterbilt use OEM coolant level modules? They usually have a black plastic body the size of a credit card, are about 10mm thick & are mounted on or near the OEM harness.

[Ambenjudah]

Not sure about a coolant level module. I just finished installing a brand new reservoir with a brand new sensor and I'm still getting the same low coolant warning.

It has a brand new wiring harness, the ecm was checked by Cummins to be good, new reservoir, new sensor.

Checked all 3 sensors that I have, all ohm out where they should. Same dang thing. I get a low coolant warning lamp and insite says fault code 0195 active: coolant level sensor 1 circuit-Voltage above normal or shorted to high source...

[Ambenjudah]

I even tried submerging the coolant sensor in a jug of water. Still didn't help, I didn't think it would. These sensors aren't actually submerged in coolant, to be honest, I have no idea how they're supposed to work. They fit up into a niche in the reservoir and never actually contact the coolant itself. I went thru the diagnostic checks again and I get down to where it says: replace ecm...but Cummins tested it and it came back good. I don't know if I have another truck here with a similar ecm to swap it out with, I'll have to look.

[Nilao]

What the coolant module looks like. Normally zip tied to the harness.

[Shandro]

(04-12-2018 )Ambenjudah Wrote:  Not sure about a coolant level module. I just finished installing a brand new reservoir with a brand new sensor and I'm still getting the same low coolant warning.

It has a brand new wiring harness, the ecm was checked by Cummins to be good, new reservoir, new sensor.

Checked all 3 sensors that I have, all ohm out where they should. Same dang thing. I get a low coolant warning lamp and insite says fault code 0195 active: coolant level sensor 1 circuit-Voltage above normal or shorted to high source...

Is it possible to see the raw data of that sensor? The actual voltage the ecm is seeing? That could help you troubleshoot a little better. Sounds like it is getting voltage from a power wire by the sounds of the code description.

[Signature620]

Just because the ecm will communicate does not mean it is good. The only way to be sure is fit a test ECM from a similar truck.

[Ambenjudah]

Well, the owner made the executive decision, disable the shutdown and just run it. It bothers me leaving stuff not fixed properly; but it's not my truck either. Thanks for all of the help everyone.

[Rawze]

(04-12-2018 )Ambenjudah Wrote:  Well, the owner made the executive decision, disable the shutdown and just run it. It bothers me leaving stuff not fixed properly; but it's not my truck either. Thanks for all of the help everyone.

Someone in the future will regret that one day.