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go-west.., Technician
Category: Medium and Heavy Trucks
Satisfied Customers: 1133
Experience:  Technican with 20 years experience focused on engines and electrical.
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2008 Freightliner Columbia 120, Detroit Engine, VIN:

Customer Question

2008 Freightliner Columbia 120, Detroit Engine, VIN: 1FUJA6CK38LAC4537Getting code
Cab Climate Control
SAE J1708 (SAE J1587) Data Link
Data erratic, intermittent, or incorrect
MID 146, SID 250, FMI 2The A/C seems to cut out periodically but then comes back (blows not cold air) and then blows cold again.
Submitted: 4 months ago.
Category: Medium and Heavy Trucks
Expert:  go-west.. replied 4 months ago.
Good evening
Are these the only codes you are getting?
Customer: replied 4 months ago.
Expert:  go-west.. replied 4 months ago.

sorry for the delay

the front hvac controller is not hooked up to the 1587 data link,remove controlller and you will see a twisted pair there.that goes to the data link juction block below the heater control inbehind the panel below the heater controller,there are usually 4 to 5 connectors that go to that junction block and the one from the heater controller might be unplugged.inspect and let me know how you do..ty

Customer: replied 4 months ago.
I took a look at the document. It says to refer to "Group 54" for further diagnosis. Do you have the pages called Group 54?
Expert:  go-west.. replied 4 months ago.
The document talks about that junction block. What did you find?

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