Accl position error

[Alpine Road Warrior]

Has anyone had a Accl position error? I assume that means accelerator position. It has come up on my silver leaf twice and then goes away. The second time I had no responce to accelerator pedal for a few seconds. Any clues?

[kraig]

I had the same problem one year ago on my Apex. At that time, I ignored the hesitation the first time. the red light came on the second time, I took it to Cummins and it was the accelerator pedal. The pedal WRV installed on mine said prototype on the side of it. I contacted the pedal application manager for Kongsburg, There wasn't one pedal anywhere in the US and it would take 6-8 weeks to get one made. Even if I found a pedal I wouldn't feel comfortable driving around if went out again and was stuck on the road. This happened at home. I called Williams Controls Tualatin OR who manufactures throttle pedals and they speced out a pedal for me. It is a truck pedal which bolts to the floor. It was in stock in Portland at Brake Systems Inc and I got it to Cummins the same day. I have been driving it for 11 months and works fine. If it were mine and that is the problem, I would switch it over. I will have to look up the part number. Hopefully you are home and if were me I would't drive it until you found out the problem. I do have a post on the forum earlier with pictures.

[Alpine Road Warrior]

The only problem is I am in Seward, AK

[kraig]

I don't know how much trouble you are having right now. You are a long ways from home. The only other thing it could be could be bad wire from the ECU. There are 6 wires. To me, it sounds like it is doing the same thing mine did. It is not hard to replace and the old one comes out in less than 5 minutes. I could try find a pedal in Portland tomorrow if you want. The pedal and the wiring kit would be a little over $300. I could tell you how to put it in ok. It is not hard. If you want you can PM me.

[Alpine Road Warrior]

Thanks for the offer Kraig. It has only done it a couple times. I think I will continue on with our trip and hope for the best until I can get to a shop. We are traveling with 3 other rigs so we are not alone.

[kraig]

Hopefully you don't need it now. I will give you the dealer and part numbers where I got my parts. Brake Systems Inc. in Portland. 503 236 2116. Williams Controls Throttle Pedal Model # WM526 Part #351571. $264. You also need connector kit Part#131773. Enjoy your trip.

[EngineerMike]

The following can be checked easily by somebody who knows how to read Pulse Width Modulated signal:
On the Teleflex pedal there is a Packard Electric Metri-Pac 150 Series 6-wire connector w/keeper, with pins labelled A-F. The wires are colored for easier tracing if needed.
A = APS Signal #1 out to ECU
B = Ground for Signal 1
C = APS Supply voltage for reference, 5VDC (presumably Signal 1)
D = APS Supply voltage for reference, 5VDC (presumably Signal 2)
E = APS Signal #2 out to ECU
F = Ground for Signal 2

What that means is there are two "Signal" circuits w/in the pedal's box above the actual foot pad. Each receives 5VDC on the two indicated wires, grounds to A or F for Signal 1 or 2 respectively, and sends out a Duty Cycle reading of 5VDC on pins B & E for Signal 1 or 2 respectively. They use two signals for the same thing as a redundant check. Usually a pedal position error indicated a difference in the two readings as would be required for them to be in sync. Imagine for example if the APS sent a signal for Wide Open Throttle erroneously w/out any check; that would be bad, hence the built in check.

Older dumber APS designs were simple rheostats, varying 0-5V on one signal and 5-0V on the other, so the sum had to be 5V.
On the Teleflex unit:
Signal 1 should vary from 11% at Idle to 42% at WOT.
Signal 2 should vary from 22% at Idle to 84% at WOT.
You can have a knowledgeable tech probe for these values to see if the pedal assembly is currently working. A transient might be no 5V reference signal (0V or some other voltage not 5V) on one or both of the middle pins, could be a loose connector, could be a loosely made wire-pin connection on one of the signal sides, could be a loose ground, , could be a poorly made connection on its way to the ECU, etc. So fixing it might not be a matter of swapping out the pedal sensor assembly, those other types of errors should be checked first, but before that I'd recommend the above Idle-to-WOT reading checks.

[Alpine Road Warrior]

Thanks E-Mike. So far so good it has been working OK. Hope to make it back to lower 48 before having it checked. Thanks for information.

[Alpine Road Warrior]

Just thought I would let you all know that I spoke with Cummins and they told me to turn key to on position and pump pedal 4-5 time from 0 -100% then back off and then start engine. We did this and so far we have not had any problems. It resets a senor. We may have the sensor changed just for peace of mind.
I waited to post this update to see if it actually works and it did. We drove from Seward, AK to Chehalis, WA. and had no problems.
Thanks to all.

[sdennislee]

Alpine Road Warrior, I'm in Anchorage if there is anything I can do let me know. There are a couple good shops here if it gets to where you need to have it serviced.

[kraig]

Glad to hear you made it back with no more problems. Mine did the exact same thing yours did at first with hesitation. I don't know about the reset. When Cummins tested all the wires up to the pedal, they said everything was fine. They said the problem was the pedal. After I replacing the pedal one year ago, everything works fine and no more error codes.