My rpm's jump about 2-400 at road speed in D and towing, warning chime abs flashes

[JRutta]

While driving at Hwy speed, my tach jumps about 2-400 rpms then back down, cruise is enguaged/disenguaged, abs light or brake light flashes on very briefly and sometimes a warning chime sounds.

Just had pcm updated at dealer... problem still persists... . no dtc's. Any Ideas?

 

[p-Bar]

Could it be the torque converter locking and unlocking it sounds like the right RPM

 

[JRutta]

Ive had it serviced regularly, now at 222,500 miles, still feel like its electrical maybe solenoid not holding pressure or debris on solenoid screen.

 

[cerberusiam]

Start checking grounds under the hood, battery cable connectiions, and batteries. Also check the trans control harness plug for fluid in the connector.

Symptoms indicate a randow power fluctuation or voltage drop to the external controls. This could be any number of things as suggested above, a rubbed wire, or a bad connection on the ECU or data bus.

What year of truck is it?

 

[JRutta]

It is an 06, only mod ive done is install a K/N cold air kit... . I really havent seen an improvement one way or the other. Seems like inly occurs when towing 25ft and 32 ft gooseneck trailer... . I can drive 150 miles and it wont act up, then it will do it ever ten miles or so. . crazy. Im gonna check connections and such. thanks.

 

[Bob4x4]

drive it with a scanner to monitor what is happening real time

 

[Prairie Dog]

Do you feel like the RPM's are really changing or is it just the tach acting up? (there are common problems with the tachs on some 06's)



If it's really changing then I kinda suspect the speed sensor in the rear end.

 

[AH64ID]

I am with Prairie Dog, I think a wheel speed sensor is acting up and trying to get trans to shift or unlock, and throwing the ABS for a loop. The cruise is also designed to disengage with a certain deceleration rate.

 

[rscurtis]

Get rid of the K&N or you're going to be chasing engine problems soon.

 

[JRutta]

I found trans fluid in connector. cleaned and will drive tommarrow on a trip to check. thanks, wil be in touch

 

[g_dog1]

Does this only happen when towing a fifth wheel? Maybe the electrical connector to the 5'er is having an issue.

 

[cerberusiam]

I found trans fluid in connector. cleaned and will drive tommarrow on a trip to check. thanks, wil be in touch

Likely it causing a short in the system that is backfeeding to the ECU. If you have fluid in there you will need to replace the harness and solenoids. Its pretty easy and inexpensive to do. FYI, when it gets bad enough the trans will stay in 1sr gear, refuse to shift, and OD likely likely not work.

 

[mfurrh55]

What does a K&N have to do with it? I've had a K&N for 12 yrs. on 2 diesels, both 5. 9 and have never had a problem with anything.

 

[Prairie Dog]

Some will argue (and argue and argue... ) that K&N allows fine dust through (known as eng dusting) and that they destroy engines.
I used one for a while and found no such effect and I suspect that much of the time this dusting was caused by someone cleaning the filter and using compressed air to dry it. I destroyed a K&N for a motorcycle that way once.
OTOH, the new thicker stock paper element breaths about 95% as good as any of the washable types so thats what I've been using.

 

[rscurtis]

It has nothing to do with your transmission problem. At best, it's a little better than a piece of window screen as an air filter. You're obviously very diligent with its maintenance, or you would have dusted an engine by now.

 

[Bob4x4]

Some will argue (and argue and argue... ) that K&N allows fine dust through (known as eng dusting) and that they destroy engines.

I used one for a while and found no such effect and I suspect that much of the time this dusting was caused by someone cleaning the filter and using compressed air to dry it. I destroyed a K&N for a motorcycle that way once.

OTOH, the new thicker stock paper element breaths about 95% as good as any of the washable types so thats what I've been using.

Well I am not going to agree with your flow percentage but the 6. 7 oem filter is something like 99% effective at its max rated flow

 

[Bob4x4]

The biggest problem with the K&N s that I see is the seal doesn't always seal allowing unfiltered air by it
They used to ship silicone grease to cost the sealing surface. I have no idea if they still are doing so now

 

[HBarlow]

I have a good friend who is a real mechanic. I met him when he worked for the nearby large volume Dodge dealer and he became my friend and mechanic. He now owns my original old '01 HO/6 speed Ram 3500.

We live out in west Texas where cotton farming is a major part of the economy. Farm work puts a lot of dust or dirt in the atmosphere. My friend has told me repeatedly of the fools who came in with late model Dodge-Cummins trucks complaining of high oil consumption and blue smoke at the exhaust. He said when a mechnic got the work ticket he drove the truck into his stall, lifted the hood, found a K&N air filter, closed the hood, and told the service manager they had another one with a dusted engine and voided warranty.

He told me it was a common occurrence.

Former TDR member BHeiting once suggested use of a section of window screen instead of a K&N filter. They were cheaper than a K&N filter to buy and filtered just as well.

I have no argument with those who want to trash their engines with a K&N filter and make believe horsepower increase but my trucks have always used OEM Fleetguard filters purchased from Geno's.

 

[Mark31]

I ran a K+N for a while in my '97 right-hand drive Cherokee until I started hearing all the bad stuff about them. My mail route had about 30 miles of dirt with some of it extremely dusty in drier weather. I sent off an oil sample, telling the lab what I was doing. The lab said there was nothing in their tests to indicate that the K+N wasn't doing a good job, but I went back to stock anyway. Mark

 

[richardcoxid]

Getting back to the original Op's post.



I had a similar problem with my ’05. Driving merrily along the TC would un-lock and re-lock for no apparent reason. The dealer CLEANED both of the Batt posts (+ and -) on both Batts and re-tightened them. He said that the ECM system was very sensitive to bad grounds.