ABS and Wheel Spin lights, No codes

Dagan Williams 33 posts since Dec 12, 2019
ABS and Wheel Spin lights, No codes Jan 13, 2021 1:56 PM
2017 FTL M2
DD ENGINE
VIN# JG0806
MI 117,215
This unit came in back in May for ABS and Wheel spin lights coming on at startup and after several hours of
T/S with no codes, both Wabco and FTL were saying it was a battery voltage low issue after truck had been
sitting and then started up, once cycling the key lights would go out and no faults would ever come active.
Truck has since returned with same issue happening more frequently and per driver happens multiple times
throughout the day even when the truck hasn't been sitting. Batteries have been replaced and verified only a
0.25 amp draw on batteries when truck is asleep and no draw when the battery switch is off. Driver came to
pickup truck and lights came on as well as CEL and Check Trans lights showing no datalink communication
on dash, hooked up computer and everything immediately began to communicate and has not had issue since
even after sitting.
Inactive codes from the last incident,
Only 1 count each
CPC: 1845/9
ABS: 639/9
TCM:193/0
CGW: 523525/14
500K Readings at this time (checked at ABS and 9 pin)
58.8ohms
2.5V High
2.38V Low
Verified BAT, IGN, and GND to ABS ECU with no significant voltage drop and load tested with headlamp.
Tags: j1939, abs, wabco, 500k, h1939, 1939

Dagan Williams 33 posts since Dec 12, 2019
Re: ABS and Wheel Spin lights, No codes Jan 13, 2021 4:38 PM
U0100 Also inactive on Allison side... did get the ABS and Wheel Spin lights back on with the TCM
disconnected but has been the only time today they have came on, leaning towards TCU issue now, verified
BAT, GND, and IGN with DMM and then load tested good.

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ABS and Wheel Spin lights, No codes

Robert Cadell Jr 2,837 posts since Nov 9, 2014
Re: ABS and Wheel Spin lights, No codes Jan 15, 2021 2:19 PM
DIDNT READ YOU COMMENT FULLY, YES I WOULD SUSPECT A TCU, IF YOU HOOK UP TO THE TCU
BY CHANCE IS THE VIN NUMBER GIBBERISH?

Dagan Williams 33 posts since Dec 12, 2019
Re: ABS and Wheel Spin lights, No codes Jan 15, 2021 3:36 PM
I will double check that when I get it back in the shop, will probably be sometime Monday or Tuesday before I
can get back to it, but I will check the VIN and rear ABS sensors then.... The comms issue is throwing me since
its only happened once, though the driver said its normal there was no stored faults for any 1939 issues.

Robert Cadell Jr 2,837 posts since Nov 9, 2014
Re: ABS and Wheel Spin lights, No codes Jan 15, 2021 3:46 PM
Maybe load test battery feeds with a headlight and ignition? No stored faults? That’s a issue.
Unless the TCU is dropping out due to a cracked circuit board, also check to see if the TCU mount
is secure.
Rob “Doc” Cadell
DTNA Master Tech/Elgin Lead Technician
Trans Chicago Freightliner BFWD
Shorewood,IL
(803)-917-5397
Good Hunting – You’ll find your problem

Dagan Williams 33 posts since Dec 12, 2019
Re: ABS and Wheel Spin lights, No codes Jan 27, 2021 4:08 PM
So CAC had me check grounds at the MGJB and the stud beside the BHM and all were good. Checked TCM
BAT, IGN, and GND again with battery voltage being 12.22V at the batteries I had 12.19V on both BAT and
IGN, load tested again and held a load with a headlamp. Reconnected to TCM and verified VIN looks to be
correct. Still throwing ABS and WHEEL SPIN lights at startup, but only after its sat for awhile with the master
switch left on for a couple days, but if I run the batteries down in the shop (leave the headlights on, radio, and
blower on high till down to 11.2V) I cant duplicate it. I let the truck sit 5 days untouched with the switch turned
off and no lights came on.

Jon Cecil 929 posts since Nov 25, 2014
Re: ABS and Wheel Spin lights, No codes Jan 27, 2021 8:07 PM

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ABS and Wheel Spin lights, No codes

I have always been told by trainers to make sure the electrical system is above 12.6 volts. If the system stays
above 12.6 volts and the lights don't come one, I would say it is a battery voltage issue as well.

Dagan Williams 33 posts since Dec 12, 2019
Re: ABS and Wheel Spin lights, No codes Feb 19, 2021 12:34 PM
Customer had been told its a battery voltage issue many times before, but I guess was never satisfied with that
answer and kept bringing it back or refusing to take it. Released the unit again after CAC said yet again that it
was a battery voltage issue and the customer finally left with the truck and has not come back yet.

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