Engine/Transmission (1998.5 - 2002) High RPM and Exhaust Brake Failure

[TRoyce]

I have a 2001 Dodge with the HO engine, the 6-speed manual transmission, an aftermarket Pac-Brake exhaust brake, and about 77,000 miles on it. Everything else is stock. I have been experiencing a high idle (1000 RPM) and an exhaust brake failure on and off for over a year. On startup and short local drives everything is fine. If I drive about 40 miles on the Interstate, when I get off, the exhaust brake will not engage and the idle will be stuck high. The idle will not return to normal unless I shut the engine off and restart it. I do not have to wait long (30 seconds) to restart the engine. The other day, when coming off the highway, the exhaust brake was not activating, the idle was high, and the ABS dash light flickered a few times (new problem). I have had this idle/exhaust brake for over a year and it is really annoying me. The dealer doesn't have a clue, and they cannot reproduce the problem. The ambient temperature doesn't matter (90 degrees F, or 20 degrees F). Sometimes, the Pac-Brake will activate intermittently when the problem occurs - in a 15 second 65 MPH to stop situation the exhaust brake might cut in and out two or three times.

I just signed up the turbodieselregistry this week to find the answer to this problem. I hope it is out there.

 

[ThrottleJockey]

Hey TRoyce,



Welcome to the TDR!



Have you pulled any codes from your ECM? You may have to do an APPS reset, too, just to get you started in eliminating various obvious and easy fixes.



Brian

 

[TRoyce]

The dealer who last looked at it said that there were no error codes in the system. This was a big reason he couldn't help.

 

[WestTN]

If your brake is connected to the ECM for control, then a high idle condition will prevent operation. You may have an APPS problem or throttle cable problem.

 

[2-ND TIME]

Exhaust brake

How is your e-brake wired is it wired seperatly? If so it could be that the electrical connections aren't making contact. Use a volt meter and check for voltage. Mine had just enought oxidization not to work.

 

[jelag]

If you have a painted brake housing..... there have been some changes... in that the new housing has a nitrate coating and is almost black... . If your having problems with the brake sticking, go to your nearest dealer and pick up a new lube that pacbrake suggests you use..... take the brake off the truck, put the brake in a vice and put a few drops in the shaft from the inside of the brake... ... let it sit a bit... . turn the brake over and do the same with the other end..... work a 20 or so times and make sure the lube gets into the base of the housing and to the end of the shaft..... I'm guessing that its good for another 3 to 5 years...



Hope this helps... if you have any additional questions email me...

 

[HBarlow]

Troyce,



Dennis McCormick is correct but a little less certain of his recommendation than I am. he left a little weasel room in his suggestion. I will retain no room to weasel out of my recommendation. I am absolutely, 100% confident and tell you with certainty, it is your APPS failing. You provided a perfect description of a failing APPS assembly. If you continue to ignore the problem eventually you will get a dead pedal. Sometimes you can effect a temporary fix by "massaging" the accelerator pedal by rapidly pressing and releasing it 20 or 30 times. I have to replace the APPS every 40k to 45k miles on my truck. I replaced three last year and one or two before that.



The first symptom you will experience with a dying APPS, if you have an exhaust brake wired through the ECM is a failure to engage the brake when you take your foot off the accelerator or disengage the cruise control to get off the interstate. The next symptom you will notice is your engine will not idle at 875 rpm like normal but will idle at 925 rpm. Those numbers may vary slightly with different trucks. If you continue driving it you will experience a complete loss of throttle input. Replace your APPS.



Added on edit: After you replace the APPS please tell this forum so that future members will be able to read this and recognize their problem.



Harvey

 

[WyattEarp]

TRoyce local member here just in the next county over, i sent you a few emails tonight on your problem... Accelerator Pedal Positioning Sensor or APPS... get back with me and maybe i can help you at least get the APPS changed.....

 

[cap-n-cray]

TRoyce,



I have or had the same problem, only I have a Jacobs exhaust brake. The brake would not work after 3-4 hours of driving. The idle would be slightly above idle to 1100 RPM, not de-fueling. I could turn the engine off for 30 seconds and it would be back to normal. Everyone I talked to say it was the APPS failing. I am still barely under warranty. I had the exhaust brake problem on my last trip towing a 8K trailer and pulled it to a Dodge dealer in Oregon to document the problem for my local dealer. It would only happen on long drives. They said it was the APPS too. The exhaust brake finally failed close to my local dealer so I took it in. Before that the dealer said that if I had no codes and it wasn't doing it so they could see it, there was nothing they would do about it. The dealer had a tech look at it and said it was not the APPS, but they would replace my VP44 pump under warranty. Since I have almost 100K, I said OK. So far the brake has not failed again. I still think the problem is the APPS. But I got a new VP44 out of it so far. I told the dealer if the brake does not work again I would like the APPS replaced.



I agree with Harvey, but I got a new VP44. Only time will tell if that was really the problem. I figure I have one more trip before I am out of warranty.



Cary

 

[djosip]

Try the easy fix shown in the lead article of the tdr web site. It is caused by the same reason as indicated in that article except the results are as you stated for a standard shift transmision. I had this on my 2001. 5 and it appears to have gone away after the foil fix. djosip