Tailer Turn Signal not working, ? Where is the trouble

[TCDiesel]

Mounting location FCM.

 

[bsappington]

Wow! Please read my post again before saying the FCM has nothing to do with the trailer lights.



All I can tell you is what I have personally done, you can tell me I am wrong all you want.



Their are tons of threads about this with directions on changing the relays. I checked the boards on the two that didn't work and I saw no burnt circuits. One of the trucks had a problem where the trailer light came on and would not blink. I am sure that was a burnt circuit.



Research a little closer and you will find that the FCM controls the horn... . Had to fix that as well...

 

[Kry226]

This is the fix. I had the same problem, and I don't have that problem anymore. I was not about to drop $500 on a new FCM so that this could happen all over again.



http://www.etrailer.com/Custom-Fit-Vehicle-Wiring,Wiring/Tow-Ready/119190KIT.html

 

[TCDiesel]

Wow! Please read my post again before saying the FCM has nothing to do with the trailer lights.



All I can tell you is what I have personally done, you can tell me I am wrong all you want.



Their are tons of threads about this with directions on changing the relays. I checked the boards on the two that didn't work and I saw no burnt circuits. One of the trucks had a problem where the trailer light came on and would not blink. I am sure that was a burnt circuit.



Research a little closer and you will find that the FCM controls the horn... . Had to fix that as well...

Just providing the neg for the Relay, TTRTR If your blinker was not working it may have just been the connection/Ground, Check the WT/PK wire in the C1 harness IPM/PDC then check the DG/WT C1 if the DG/WT wire is hot when Left turn (On) its unlikely the FCM is the culprit. Chris My Partner does the tech/Dia, You may have needed to replace the FCM,But we have NEVER encountered it for rigth turn trailer tow.



FRONT CONTROL MODULE

DESCRIPTION

The Front Control Module (FCM) is a micro con¬troller based module located in the left front corner of the engine compartment. On this model the inte¬grated power module must be positioned aside in order to access the front control module. The front control module mates to the power distribution cen¬ter to form the Integrated Power Module (IPM). The integrated power module connects directly to the bat¬tery and provides the primary means of circuit pro¬tection and power distribution for all vehicle electrical systems. The front control module controls power to some of these vehicle systems electrical and electromechanical loads based on inputs received from hard wired switch inputs and data received on the PCI bus circuit (J1850).

For information on the Integrated Power Mod¬ule Refer to the Power Distribution Section of the service manual.

OPERATION

As messages are sent over the PCI bus circuit, the front control module reads these messages and con-trols power to some of the vehicles electrical systems by completing the circuit to ground (low side driver) or completing the circuit to 12 volt power (high side driver). The following functions are Controlled by the Front Control Module:

• Headlamp Power with Voltage Regulation

• Windshield Wiper “ON/OFF” Relay Actuation

• Windshield Wiper “HI/LO” Relay Actuation

• Windshield Washer Pump Motor

• Fog Lamp Relay Actuation

• Park Lamp Relay Actuation

• Horn Relay Actuation



The following inputs are Received/Monitored by the Front Control Module:

• B+ Connection Detection

• Power Ground •

Ambient Temperature Sensing

• Ignition Switch Run

• Washer Fluid Level Switch

• Windshield Wiper Park Switch

• PCI Bus Circuit

 

[bsappington]

Listen, it is not my intention to argue with you. I respect your information about the burnt trace. I am just not really understanding why you would tell me that I am wrong since YOU have never seen the condition I am talking about. You say the FCM has nothing to do with the trailer lights, however, in the diagram that you post above on the left it clearly show that the FCM activates the coils on the relays for Left, Right and Park of the three relays attached to the back side of the circuit board in the PDM.



How does this mean that the FCM has nothing to do with the trailer lights. Is it because it is not listed in the writting next to the drawing?

 

[bsappington]

This is the fix. I had the same problem, and I don't have that problem anymore. I was not about to drop $500 on a new FCM so that this could happen all over again.



http://www.etrailer.com/Custom-Fit-Vehicle-Wiring,Wiring/Tow-Ready/119190KIT.html

This was my plan "B" if the relays didn't work. I am with you.

 

[brillmtb]

So the relays can be swapped out as a possible fix on the PDC/IPM without replacing a 500 dollar board? I think I should start there there and drop my fuses to 10 amp

 

[brillmtb]

Wow, lots of boards inside the PDC. Can anyone help me as to where the right relay is.

 

[seafish]

This was my plan "B" if the relays didn't work. I am with you.

I am NOT saying that the modulite relay isn't a good idea, BUT do realize that it is made from cheap silicon relays, and can fail, thus causing it's own lighting issues. Here is the thread--





https://www.turbodieselregister.com/forums.384/showthread.php?t=237981

 

[brillmtb]

Can I express some frustration. So my 20k accura had not mechanical or electric issues for its lifetime and my no 50k to replace truck has all this cheap circuits and now my washer motor went out. What the heck are we paying for.

 

[TCDiesel]

Listen, it is not my intention to argue with you. I respect your information about the burnt trace. I am just not really understanding why you would tell me that I am wrong since YOU have never seen the condition I am talking about. You say the FCM has nothing to do with the trailer lights, however, in the diagram that you post above on the left it clearly show that the FCM activates the coils on the relays for Left, Right and Park of the three relays attached to the back side of the circuit board in the PDM.



How does this mean that the FCM has nothing to do with the trailer lights. Is it because it is not listed in the writting next to the drawing?

Your right about the activation By grounding the relays... O I didn't mean to offend or disagree. . I cannot count the times we have seen NEW FCM bolted to the real problem that some owner replace because it was the most popular choice on the social network. Just think how many days a Day through America that Techs/Service personnel have to deal with the same Question " I read on some forum the X is the problem" Nothing wrong with being informed or knowledgeable ,But at times... . give the shop 1st discretion to see what comes of it.

 

[TCDiesel]

No. . its the facts. . Until you have your own shop. . and answer 100s of questions free of charge. . 8 to 12 hrs 5+ Day Weekly. . Your freedom of speech does NOT measure up. If you are that great why not open your own shop and make the big $$$$$$$. Its allot tougher to fool someone standing in your place of business. I think you may find yourself in the court of jurisdiction frequently.

 

[TCDiesel]

Prairie Dog, Grow some skin. . Most of your posting is NOT Part of the Social Network I am talking about, I enjoy your comments and find them useful.

 

[bsappington]

No. . its the facts. . Until you have your own shop. . and answer 100s of questions free of charge. . 8 to 12 hrs 5+ Day Weekly. . Your freedom of speech does NOT measure up. If you are that great why not open your own shop and make the big $$$$$$$. Its allot tougher to fool someone standing in your place of business. I think you may find yourself in the court of jurisdiction frequently.

I suppose there were some posts that were removed. I am going to guess these comments weren't pointed at me. I case they were I am a shop owner. Just cause I said I work there part time does not mean I don't know what I am talking about. My day job is working for a Cruise Ship company looking after all of the main engines in the fleet.



I believe you are right, some places do point toward the most expensive part and say change this then call me. Fact is I pulled one customers PDM and changed the relays to try to solve his problem while he waited. It didn't work. We didn't charge for the labor or the relays. Fact is we told the guy we tried and we were wrong. You need to change your FCM and no charge for anything we did. We did not feel right charging for labor when we fixed nothing. I believe that is how a business should be run.

 

[TCDiesel]

I suppose there were some posts that were removed. I am going to guess these comments weren't pointed at me. I case they were I am a shop owner. Just cause I said I work there part time does not mean I don't know what I am talking about. My day job is working for a Cruise Ship company looking after all of the main engines in the fleet.



I believe you are right, some places do point toward the most expensive part and say change this then call me. Fact is I pulled one customers PDM and changed the relays to try to solve his problem while he waited. It didn't work. We didn't charge for the labor or the relays. Fact is we told the guy we tried and we were wrong. You need to change your FCM and no charge for anything we did. We did not feel right charging for labor when we fixed nothing. I believe that is how a business should be run.

I hear Ya. . We run on the same Platform. . Again sorry for the confusion.

 

[Prairie Dog]

TC your problem is, you answer those questions whether you know what your talking about or not and profess to know all when we've had posters that have made it clear, you don't . (I still remember when you were going to delete all your posts and never come back because someone more knowledgeable corrected you)
When someone comes on here with another point of view, experience or just has far more training than you, you find some way to demean or insult them.
Your "Social Media" slam is the best. I have found that these and other forums collectively blow you out of the water. At the same time people have gained a wealth of knowledge by sharing info and that knowledge that has saved them plenty.
How do you know that I haven't spent 12 hours a day on the phone helping customers? As a matter of fact I have and that leads me to another point;
Given your complete lack people skills, how on earth could you have spent that much time in the CS field?

Now. why don't I open my own shop? Because I learned how to talk to people without talking down to them, I was successful enough that I don't have to work.

 

[TCDiesel]

TC your problem is, you answer those questions whether you know what your talking about or not and profess to know all when we've had posters that have made it clear, you don't . (I still remember when you were going to delete all your posts and never come back because someone more knowledgeable corrected you)

When someone comes on here with another point of view, experience or just has far more training than you, you find some way to demean or insult them.

Your "Social Media" slam is the best. I have found that these and other forums collectively blow you out of the water. At the same time people have gained a wealth of knowledge by sharing info and that knowledge that has saved them plenty.

How do you know that I haven't spent 12 hours a day on the phone helping customers? As a matter of fact I have and that leads me to another point;

Given your complete lack people skills, how on earth could you have spent that much time in the CS field?



Now. why don't I open my own shop? Because I learned how to talk to people without talking down to them, I was successful enough that I don't have to work



Yep. . I could only wish I know it all. . I am far form perfect and make mistakes often thats what seperates YOU & ME.

 

[Prairie Dog]

Oh brother.