I was hoping somebody out there can help. My transmission goes into system malfunction. All the time. It don't matter what gear. I am wondering if replacing the wire harness and reprogramming the tcu might help.that is the only thing that the dishonest Mechanics have not recommended.
Meritor transmission problems
- Thread starter Theironmantools
- Start date
No the truck goes into sm, at anytime in any gear Manuel or automatic
Sounds like a job for EO's very own greasytshirt
Does anybody have any experience with the meritor freedom line zf transmission. I already know its a piece of junk. But I'm trying to get it to work for a few weeks.
Don't look at me!
Mine did that for a little while, that is most likely a 24 volt system, and a drop in power will throw the ECM in to default. I would start with checking batteries and alternator. Those would be the cheap and easy fixes, if that's not it then their is the voltage doubler, ECM, or wiring harness. Good luck that is a great transmission as far as hard parts. But the electronics can be a nightmare.
Hope this helps
Yes it might thank you.
Our truck had a Meritor transmission that would go into SM most times it rained, and sometimes when it was cold. The truck and transmission worked fine in that SM state. We could manually shift through the gears, but the automatic transmission function went away. When these failures occurred, a few miles of dry-road running or a fully-warmed truck would bring back auto-shifting and the SM code on the dash would disappear on its own.
To us, this was a minor irritation; not something to go out of service for to get fixed. The diagnosis would be difficult and time consuming, since the problem was intermittent. Had we set course to a dealer when the SM code appeared, the code would likely disappear before we arrived. In the years we owned the truck, it never happened that we drove to the shop for other reasons and the SM code was then active.
Writing down the codes and conditions for later reference did not help. The technicians we talked to about it wanted to catch the malfunction in the act. The codes they pulled were interesting to them, but without a smoking gun, they were reluctant to attempt a fix. Some repair attempts were made like replacing an ABS sensor that the codes reported and replacing a harness (warranty repair). Those attempts did not resolve the issue.
When we sold the truck, the issue was disclosed to the buyer and he did something we were never willing to do. He took the gamble and threw parts at the problem. He had all ABS sensors and a couple of other sensors replaced. According to a report from him later received and happily made, that solved the problem. With over 750,000 miles then on the truck, the transmission worked perfectly, warm or cold, rain or shine.
In this case, it was not a transmission issue per se. The Meritor transmission was not a piece of junk (as one member stated above), one or more sensors were junk. The fact that issue was resolved when a number of sensors were replaced, but not resolved when one code-indicated ABS sensor was replaced leads me to believe that two or more sensors were defective in some way at the same time.
In such a situation, all sorts of weird signals and/or codes might be generated that could be meaningless or misleading. In such a case, a skilled technician could put hours into diligently following every diagnostic procedure in the book and still not uncover the real issue. The truck buyer's willingness to shoot from the hip and gamble on the result proved to be the wise course.
To us, this was a minor irritation; not something to go out of service for to get fixed. The diagnosis would be difficult and time consuming, since the problem was intermittent. Had we set course to a dealer when the SM code appeared, the code would likely disappear before we arrived. In the years we owned the truck, it never happened that we drove to the shop for other reasons and the SM code was then active.
Writing down the codes and conditions for later reference did not help. The technicians we talked to about it wanted to catch the malfunction in the act. The codes they pulled were interesting to them, but without a smoking gun, they were reluctant to attempt a fix. Some repair attempts were made like replacing an ABS sensor that the codes reported and replacing a harness (warranty repair). Those attempts did not resolve the issue.
When we sold the truck, the issue was disclosed to the buyer and he did something we were never willing to do. He took the gamble and threw parts at the problem. He had all ABS sensors and a couple of other sensors replaced. According to a report from him later received and happily made, that solved the problem. With over 750,000 miles then on the truck, the transmission worked perfectly, warm or cold, rain or shine.
In this case, it was not a transmission issue per se. The Meritor transmission was not a piece of junk (as one member stated above), one or more sensors were junk. The fact that issue was resolved when a number of sensors were replaced, but not resolved when one code-indicated ABS sensor was replaced leads me to believe that two or more sensors were defective in some way at the same time.
In such a situation, all sorts of weird signals and/or codes might be generated that could be meaningless or misleading. In such a case, a skilled technician could put hours into diligently following every diagnostic procedure in the book and still not uncover the real issue. The truck buyer's willingness to shoot from the hip and gamble on the result proved to be the wise course.
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Usually not always when my truck goes into sm, system malfunction. It won't shift but it will stay in whatever gear it was in.a big problem is nobody either knows how to work on then or they hate working on them.and freightliner is the only place to go that has the right software.
Is the air pressure over 100lbs? Also, this is going to sound weird but ABC bus company, there are the sol imported of Vanhool Charter buses. A lot of these bus have the ZF tranny mite he worth a shot to look them up, they have train mechanics just for the ZF tranny. They are all over the USA not sure where you are located.
TruckingSurv
Seasoned Expediter
The truck I drove until earlier this year had the same gearbox and got the SM once in a while, as Phil pointed out it seemed related to moisture and always seemed to heal itself, a bad sensor does make a lot of sense.
TS
TS
What I've learned since I've had this meritor junk. Is nobody is qualified to work on it. And if I get somebody that does spend five or ten minutes looking at it . all they do is guess as to what is needed to repair the problem. Nobody recommends the same thing twice.
TruckingSurv
Seasoned Expediter
ZF builds decent stuff, although there does seem to be more electrical/sensor issues with these than there should be, the real issue with this gearbox as has been alluded to, no shops really know much about it, this is mostly due to limited years in the USA and then ZF leaving the US market. This gearboxes were only used for maybe years 2006-2009 or something like that, ZF sued Eaton for antitrust and they ended up winning a $500 million settlement against Eaton, I think for whatever reasons they bailed out of the US truck market about the time the suit was settled or maybe during the pending outcome, basically this left the existing users as orphans in the US market with limited shops who knows how to work on them and I suspect no support from ZF either.
TS
TS
Doe's anybody know how I could test the sensors and the ecm, so far I have a voltage doubler coming. I'd rather not have to purchase each part . unless I know there bad.
I hope it does too. Thank you!
That may be a good approach, but in the case of a sensor that sometimes works and sometimes fails, testing it may not indicate a problem. You may be testing it when the occasionally-defective sensor is working perfectly.
Did anybody. Buy a tcu rebuild kit. Instead of replacing the tcu.