Factory brake controller

[Joseph Sobiech]

I have a 2017 ram 3500 I tow a 18000 pound toy hauler camper there are 3 axles 6 breaks. I have taken aback several times the last time they have changed the brake controller. But I still had the same problem I am only getting 6.5 V to my tires the brake controller just does not put out enough voltage has anyone out there have this problem and if so what was the solution.

 

[amauri]

I don't tow anything that heavy with my 2018 2500 and you may already know this, but did you try the heavy trailer setting thru the trailer brake setup menu?

 

[jgillott]

Pm forum member JR. If I remember correctly he had similar issues with his controller when he first got his truck. I believe it was a wiring issue in the trailer itself but I don't remember for sure.

Anyway, he may be able to help you track this problem down.

 

[Wiredawg]

My 5er weighs 21Klbs and I run with the controller set on heavy, and max 10 on intensity. It stops the 2 axle electric/hydaulic brakes fine. I never checked voltage, but will after I recover from recent surgery.

Cheers,

Ron

 

[JR]

At what speed are you measuring voltage? I believe 15+ models the ITBM only allows 70% of max voltage below 30mph, or roughly 7 volts. I am not positive if this programming continued into the 17 model year.

 

[Dan_69GTX]

Also, where are you measuring voltage? At the magnet or at the connection at the truck/trailer plug? If at the magnets are all magnets the same voltage? Then also check the voltage at the truck/trailer to see if there is any drop.

If the voltage at the truck plug (while plugged into the trailer) is much greater, you have a wiring issue. Another test - disconnect plug from truck, pull the break-a-way and see what the voltage at the magnet is compared to the trailer battery.

So, what is your problem? Not enough braking force?

 

[Wiredawg]

At what speed are you measuring voltage? I believe 15+ models the ITBM only allows 70% of max voltage below 30mph, or roughly 7 volts. I am not positive if this programming continued into the 17 model year.

I have the Tech Authority 2017 Ram Cab and Chassis Service Manual CD Here is one of the troubleshooting checklists:

Theory of Operation


The Integrated Trailer Brake Module (ITBM) communicates with the vehicle through the high speed CAN C bus. The ITBM monitors the Brake Pedal Status, Vehicle Speed and ESP status via CAN message. It also outputs the Trailer Status, Gain Setting, and Trailer Brake Output Power to the vehicle. The ITBM connects to the electric trailer brakes through the 7-Way connector and controls the brake force through a Pulse Width Modulating (PWM) duty cycle.

NOTE: If there is no trailer connected there will be NO Pulse Width Modulating (PWM) signal.

The PWM is proportional to the rate of deceleration measured by the accelerometer inside the ITBM. The ITBM controls the PWM output to the trailer brakes in four ways. The first occurs while the brake pedal becomes active and vehicle speed is greater than 0 km/h (0 mph). The second is the manual lever on the ITBM that can be controlled by the driver. If both the manual lever and the brake pedal are active simultaneously, the greater of the two, in terms of PWM output, will prevail. The third is after the vehicle has stopped moving, after approximately three seconds of the brake pedal applied the trailer brakes will be applied too. This is to minimize hitch to trailer noise and vehicle roll back when taking off from a stop and on an incline. The fourth is that it will become active during an ESP trailer sway event.

. When Monitored:

• Continuous.
  
  
• Set Condition:
  If the Integrated Trailer Brake Module (ITBM) is configured incorrect or the ignition voltage is below 9v or greater than 16v, this code will set. Automatic braking and manual lever braking (squeeze switch) are disabled.
  

Possible Causes
TRAILER WIRING/BRAKES
(F943) IGNITION RUN/START CONTROL OUTPUT CIRCUIT OPEN OR HIGH RESISTANCE
(A115) FUSED (B+) CIRCUIT OPEN OR HIGH RESISTANCE
(Z905) GROUND CIRCUIT(S) OPEN OR HIGH RESISTANCE
INTEGRATED TRAILER BRAKE MODULE (ITBM)

1.
NOTE: The appropriate trailer or trailer simulator must be present for the results of this test to be valid.

NOTE: This DTC must be active for the results of this test to be valid.
DTC IS ACTIVE

1. Connect the trailer or trailer simulator to the vehicle.
2. Ignition on, engine not running.
3. With the scan tool, record and erase DTCs.
4. Cycle the ignition switch from off to on.
5. With the scan tool, read DTCs.

Is the status Active for this DTC?

Yes go to 2

No go to 7

2.TRAILER WIRING/BRAKES

1. Turn ignition off to the lock position.
2. Disconnect the trailer or trailer simulator from the vehicle.
3. Ignition on, engine not running.
4. With the scan tool, record and erase DTCs.
5. Cycle the ignition switch from off to on.

Does the ITBM display "CF"?

Yes go to 3

No: Trailer wiring/brakes are inoperative, refer the customer to an authorized trailer dealer.

3.(F943) IGNITION RUN/START CONTROL OUTPUT CIRCUIT OPEN OR HIGH RESISTANCE


1. Turn ignition off to the lock position.
2. Disconnect the ITBM C2 harness connector.
3. Check connectors - Clean/repair as necessary.
4. Ignition on, engine not running.
5. Using a 12-volt test light connected to ground, check the (F943) Ignition Run/Start Control Output circuit.

NOTE: Compare the brightness to that of a direct connection to the battery.

Does the test light illuminate brightly?

Yes go to 4

No Repair the (F943) Ignition Run/Start Control Output circuit for a short to ground, an open circuit, or high resistance.
Perform the ITBM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Integrated Trailer Brake (ITBM) - Standard Procedure).

4.(A115) FUSED (B+) CIRCUIT OPEN OR HIGH RESISTANCE


1. Turn ignition off to the lock position.
2. Disconnect the ITBM C1 harness connector.
3. Check connectors - Clean/repair as necessary.
4. Ignition on, engine not running.
5. Using a 12-volt test light connected to ground, check the (A115) Fused (B+) circuit.

NOTE: Compare the brightness to that of a direct connection to the battery.

Does the test light illuminate brightly?

Yes go to 5

No Repair the (A115) Fused (B+) circuit for a short to ground, an open circuit, or high resistance.
Perform the ITBM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Integrated Trailer Brake (ITBM) - Standard Procedure).

5.(Z905) GROUND CIRCUIT OPEN OR HIGH RESISTANCE


1. Turn ignition off to the lock position.
2. Using a 12-volt test light connected to B+, check the (Z905) Ground circuit.

NOTE: Compare the brightness to that of a direct connection to the battery.

Does the test light illuminate brightly?

Yes go to 6
No Repair the (Z905) Ground circuit(s) for an open circuit or high resistance.
Perform the ITBM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Integrated Trailer Brake (ITBM) - Standard Procedure).


6.INTEGRATED TRAILER BRAKE MODULE (ITBM)

1. Turn ignition off to the lock position.
2. Disconnect the trailer.
3. Using the wiring diagrams as a guide, check all related splices and connectors for signs of water intrusion, corrosion, pushed out or bent terminals, and correct pin tension. Pay particular attention to all Power and Ground circuits.


Were there any problems found?

Yes

• Repair as necessary.
• Perform the ITBM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Integrated Trailer Brake (ITBM) - Standard Procedure).

No

• Replace the Integrated Trailer Brake Module (ITBM) in accordance with Service Information. (Refer to 08 - Electrical/8E - Electronic Control Modules/MODULE, Integrated Trailer Brake (ITBM) - Removal).

7.INTERMITTENT WIRING AND CONNECTORS

1. The conditions necessary to set this DTC are not present at this time.
2. Using the wiring diagrams as a guide, check all related splices and connectors for signs of water intrusion, corrosion, pushed out or bent terminals, and correct pin tension.
3. Wiggle test the wiring harness and connectors while monitoring the scan tool data relative to this circuit.
4. Look for the data to change or for the DTC to reset during the wiggle test.
5. While monitoring the scan tool data relative to this circuit.
6. Connect the trailer to the vehicle.
7. Look for the data to change other than as expected or for the DTC to reset.


Were any problems found?

Yes

• Repair as necessary. Possible trailer wiring problem, refer the customer to an authorized trailer dealer.
• Perform the ITBM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Integrated Trailer Brake (ITBM) - Standard Procedure).

No

• Test complete, the condition or conditions that originally set this DTC are not present at this time.

 

[Newsa]

At what speed are you measuring voltage? I believe 15+ models the ITBM only allows 70% of max voltage below 30mph, or roughly 7 volts. I am not positive if this programming continued into the 17 model year.

I don't think the voltage reduction applies when pulling the manual lever? That might adversely affect calibration when hooking up a new or unfamiliar trailer?

 

[Cummins12V98]

I miss my MaxBrake

 

[Joseph Sobiech]

I don't tow anything that heavy with my 2018 2500 and you may already know this, but did you try the heavy trailer setting thru the trailer brake setup menu?

Yes have it in heavy and maxed out on 10.

 

[Joseph Sobiech]

I have had my trailer checked out is was fine also hook up a GMC and a Ford git 11.1 volts. I and the mechanics test at the junction from the 5th wheel brake wire. I have my truck on heavy electric and maxed out on 10. My problem is I cannot stop the camper. If I ever had to stop fast it's not going to be good. If I am rolling and squeeze the manual to max 100% the truck just keep on rolling. This sucks. Spent alot of money for it not to work.

 

[EZeis]

Do you have the lastest software?


Earl

 

[Joseph Sobiech]

Yes when I took it to the dealer they told me they updated it.

 

[jhenderson]

There’s been plenty of discussion about the operation of the ITBM. It’s obvious that the engineers who designed this unit never pulled a heavy trailer. Your best option is an aftermarket controller. I like the reviews of DirecLink.

 

[Dan_69GTX]

When I got the new truck I had issues with the trailer brakes not applying properly to stop in a reasonable distance. The trailers worked fine with 3 other vehicles - all older with add-on brake controllers.

I finally replaced the wire on BOTH TRAILERS going to the brakes and all worked just fine then. The wires were compromised and the new controller didn't play well till the wires were repaired (in this case, replaced).

 

[Wiredawg]

I have had my trailer checked out is was fine also hook up a GMC and a Ford git 11.1 volts. I and the mechanics test at the junction from the 5th wheel brake wire. I have my truck on heavy electric and maxed out on 10. My problem is I cannot stop the camper. If I ever had to stop fast it's not going to be good. If I am rolling and squeeze the manual to max 100% the truck just keep on rolling. This sucks. Spent alot of money for it not to work.

Joe, when I first set mine up on my 5500, I had concerns, before I read the info I posted above about how the controller operates. I have had an emergency stop at over 33K lbs GCW and I stopped great. I have the controller set to max settings, just like I had all the manual brake controllers in the past.

I hoped cutting pasting the OEM manual brake controller instructions would help, but no one seems to be interested. It seems to me the Pulse Width Modulation signal is key here, and understanding how it is determined and how it effects actual trailer braking will help figure out the problem. One more thing, the OEM manual using a 12vdc light to measure brightness from direct connect to battery to brightness in braking system sucks. They should be using a multi meter. So there is an FCA short sight in troubleshooting a complex system with a light. I dont even own a test light....I carry a multimeter in the door of my truck. It gets used a lot on the road. mostly helping other campers.

I'm not saying you dont have a problem, just saying it's a complex one that operation has to be understood in order to fix or optimize it.

One thing I know for sure, "smart Devices" that operate in fractions of seconds based upon multiple inputs, to provide a measured output to deliver a desired outcome is huge.

For my own part, I'm down from a surgery right now, but when I get back on my feet, I plan on going through every connector on my 5th wheel associated with brakes (and some other citcuits) inspect, add dielectric grease, which I'll bet a bag of doughnuts, isn't there, in order to optimize my braking system. Since this is an electric braking system, what is the trailer brake impedance operating range? Are the trailer brakes optimally adjusted? especially magnet drum type?

Finally, I hope the info I posted helps and maybe I'll start a thread to see all the heavy haulers experiences and settings. Do all us heavy haulers have brake controller set at max settings? How about braking performance and customer confidence levels.

Good luck finding the problem. We'll continue to follow and help as we can.

Cheers Ron

 

[Dan_69GTX]

OHH - thanks for reminding me to recoat my connections with dielectric grease!

Yea, this thing is complex - like all the other stuff on the truck. Hopefully Joseph can use your post to help figure out the problem.

 

[EZeis]

I've read all the issues on the factory controller. They must of changed something as my August built 2018 works perfectly. Way way way better than the worthless P3 I had in my previous truck.
Also mine must be sensing brake hydraulic pressure. If I'm stopped I can vary the gain bar by varying the brake pedal. So it's either a pressure sensor or a pot on the pedal. No other way for it to "see" brake pedal/hydraulic pressure change like that.


Earl

 

[Joseph Sobiech]

I can be rolling to up to a stop sign at 10 to 15 mph and squeezed the manual brake controller and roll thru the sign. It's like the brake controller cannot handle the load of the 6 wheel magnetic brakes.

 

[Newsa]

I can be rolling to up to a stop sign at 10 to 15 mph and squeezed the manual brake controller and roll thru the sign. It's like the brake controller cannot handle the load of the 6 wheel magnetic brakes.

My 2013 will easily lock up trailer brakes with the manual slide controller if i set the gain above 6