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Jeremy, Certified Truck/Bus Technician
Category: Medium and Heavy Trucks
Satisfied Customers: 3219
Experience:  ASE Med/HD Truck Technician, NATEF Diesel Engines and Electrical/Electronics Technician, EPA 608/609 HVAC Certified, Steering/Suspension and ABS/Brakes Technician
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I am having problems with 2013 Freightliner Cascadia? Can

Customer Question

I am having problems with 2013 Freightliner Cascadia? Can you help me?
JA: Thanks. Can you give me any more details about your issue?
Customer: When I plug up a trailor, the marker lights for the turn signals and 2 of the rear tail lights do not work. Turn signals and brake lights still work, top marker lights still work. Already changed pigtail and checked all fuses under hood.
JA: OK got it. Last thing — Technicians generally expect a deposit of about $54 to help with your type of question (you only pay if satisfied). Now I'm going to take you to a page to place a secure deposit with JustAnswer. Don't worry, this chat is saved. After that, we will finish helping you.
Submitted: 1 year ago.
Category: Medium and Heavy Trucks
Expert:  Jeremy replied 1 year ago.

Have you checked to verify that the issue is at the pigtail by checking all the pins and it's not in the trailer 7 way box or a feedback off the traiper causing the lighting module to turn those circuits off on the trailer? The Cascadia has a circuit protection in the lighting module that if roo much resistance is being returned that it will shur the circuits down to protect the wiring and the module.

Expert:  Jeremy replied 1 year ago.

I would check the trailer to make sure there are no issues with it by using a trailer tester.

If the pigtail is out, cycle the key 6 times to reset the module and retest with a pigtail tester.

Customer: replied 1 year ago.
I have replaced the pigtail, checked all fuses in the Sam module under the hood on driver side and fuses behind the glovebox, all fuses are good and pigtail didn't fix problem. Top marker lights work bottom ones don't (side and rear) brake lights and turn signals also work
Expert:  Jeremy replied 1 year ago.

Did you test the circuits on the pigtail to verify the issue is in the truck? You never answered that. If so,how did you test and what pin numbers have power and don't have power?

Customer: replied 1 year ago.
No but the last 5 trailers have had the same issue
Expert:  Jeremy replied 1 year ago.

Do you have codes on the dash for the lighting module? You should have codes for the fault to indicate circuit high, low, fail, etc. Thos will help guide a short to power, short to ground, ligthing module itself failing, etc. It will usially always come up one the dash for it.

Customer: replied 1 year ago.
No codes
Expert:  Jeremy replied 1 year ago.

No codes means it's reading a fault from the trailer. Check the ground wire at the back of the truck where it meets the pigtail. There is a connector there with a rubber insert. Pull that apart and make sure the rubber didn't let water by. Trace that down to under the vab to the connector on the frame and make sure no water or loose pin on that plug as well. It will be on the left, about even with the door on the frame.

There is a bad return getting to the module and it's kicking the lights out or you had a trailer that kicked the module off and it didn't come back on.

Try doing the 6 cycle of the key reset and if a no go, then Freightliner Service Link will need to be used to reset the module to get the circuits oowered back on.

It's going to be ome of those issues since there are no codes. The lighring module is very good for throwing codes when there are circuit problems on this model of truck.

Customer: replied 1 year ago.
I pulled out the plug on the back of the cab and mine is solid, you can't pull the back of it apart. It can be pulled out and there are plastic clips that allows it to be unplugged. It pulls out about 12" then there are 2 clips one is a ground and the other is the positive wires I assume
Expert:  Jeremy replied 1 year ago.

You'll need the Freightliner Service Link to diagnose this issue then.

I'm going to opt out for at this point, this will need a hands on approach which is difficult to do on the internet.

Good luck to you!

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