Intermittently shutting down and low coolant warning

[Ambenjudah]

Hey guys,

I have a Peterbilt manufactured in 01/2008 model 367 with an ISX 485 CM870. It started with a low coolant warning. The lead mechanic at the main shop replaced the sensor and decided to just change it to a warning lamp instead of a shutdown and then just turned it back out the door.

Shortly thereafter it started shutting down intermittently. Sometimes it will start right back up, other times you have to wait a bit.

It doesn't throw a code at all when it shuts down.

There is a constant code of low coolant that's all.

I'm stumped on to why it could be shutting down. I found some information about it possibly being ecm issues but can't find out where the disconnect is. Ugh.

Any type of help would be appreciated. Feel free to move this to wherever it needs to be.

Thanks guys.

[Rawze]

maybe this helps...
http://rawze.com/forums/showthread.php?t...1#pid16241

[Ambenjudah]

Ok, so I did what the links pointed out. Short of replacing the ecm (we don't have a spare). During my checking of everything:

Cleaned and tested batteries. All Optima Yellowtops straight from the factory. All good.

Removed power cable to ecm and checked the whole length of it for any issues. Re wire loomed it and re installed.

Replaced the two 15amp fuses in the battery box along with the 20amp inline fuse underneath the ecm.

Removed the coolant sensor and replaced with a known good one. Tested the coolant sensor wiring to make sure it is good. I am getting 5v to it and very close to that on the return signal wire.

Checked and replaced every fuse under the kick panel on driver side. Replaced the circuit breakers to be safe. Tested all relays behind the dash above the steering column.

After this, I plugged into insite and the low coolant warning was still flashing (there is plenty of coolant in it) and the following codes were present:

0197-active coolant level-data valid but below normal operating range-moderately severe level

0132-inactive accelerator pedal or lever position sensor 1 circuit-Voltage below normal or shorted to low source

1241-inactive accelerator pedal or lever position sensor 2 circuit-Voltage below normal or shorted to low source

1881-inactive after treatment dpf differential pressure sensor circuit voltage below normal or shorted to low source

1117-inactive power supply lost with ignition on-data erratic, intermittent, or incorrect

0195-inactive coolant level sensor 1 circuit-Voltage above normal or shorted to high source.

I also traced the coolant sensor wires as far as I could back to where it goes in to the main loom.


The only other thing I can think of is there is an issue somewhere in the loom that I'm unable to find or the ecm is bad.. I was able to clear the inactive codes and they didn't return. According to quikserve they all share the same return signal pin in the harness (unsure how that works).

I'm at my wit's end and the big boss in Portland is starting to get antsy. Which is pretty normal but a pain in the rear.

Thanks for any and all help.

[Rawze]

All those errors almost sounds like a programming issue...

Make sure it is not the ECM that has lost its programmed addresses for those inputs while you are at it. Sometimes re-flashing an ecm can cause this. Also, with CM870's in particular, you should not try to re-flash the ecm from the J1708 harness in the dash. You always need to do it from the J1939 "weather-pack" connector out at the engine.

[Ambenjudah]

Thanks Rawze. I think we're going to pull the ecm and take it up to Cummins NW here and have them plug it in.

I've thought it was more than likely going to end up at this point but the owners would rather take every other measure before jumping to a likely cause.

I'll let you know what happens.

[Ambenjudah]

Sent the ecm over to Cummins. They hooked it up and it is communicating properly. Ordered up a new harness which should be here next week.

[Ambenjudah]

Alright folks. Got a new oem engine harness installed, everything works great except I'm still getting a low coolant warning. Have tried 2 known working coolant sensors. I'm stumped now. I read somewhere that the reservoir itself may be an issue...

I did find multiple issues in the harness but I don't know where to go from here.

[Waterloo]

(04-11-2018 )Ambenjudah Wrote:  Alright folks. Got a new oem engine harness installed, everything works great except I'm still getting a low coolant warning. Have tried 2 known working coolant sensors. I'm stumped now. I read somewhere that the reservoir itself may be an issue...

I did find multiple issues in the harness but I don't know where to go from here.

Don't quote me, but I believe the PACAR trucks have a goofball coolant jug. There is the sensor and then a magnet below that if I remember correctly. That magnet, or weight, or whatever it is sticks. The only way to repair properly is to get a new coolant bottle. Someone will correct me if I am wrong.

[PeteMelb]

(04-11-2018 )Ambenjudah Wrote:  Alright folks. Got a new oem engine harness installed, everything works great except I'm still getting a low coolant warning. Have tried 2 known working coolant sensors. I'm stumped now. I read somewhere that the reservoir itself may be an issue...

I did find multiple issues in the harness but I don't know where to go from here.

I have just fixed the second one of our trucks giving the same coolant issue code and on both trucks it was the wires going into the sensor connector not the sensor itself, the wires looked ok but were broken inside right at the connector.