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 IHC 444E won't rev up; Chk eng light on
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Donguy
New Member

7 Posts

Posted - 03/20/2017 :  8:29:40 PM  Show Profile  Visit Donguy's Homepage  Reply with Quote
I have a 2003 444 E that has an intermittent problem of suddenly not being able to rev up the engine with the pedal. The code tells me that the two switches in the pedal are conflicting.
Put on a new tps and no change. I've followed the troubleshooting guide using J 1703 program, and everything up to the point of using a breakout box checkout within specs. I tried a known good ECM ( 1 box system) and another dead end. Fuses are good at battery and inside dashboard.
I'm at a loss as to where to go next to check.
The trouble is it may drive perfect for a day or a week and then all of a sudden it won't.
Can anyone help? Thx.

Dvorak
Senior Member

United States
95 Posts

Posted - 03/21/2017 :  03:55:11 AM  Show Profile  Reply with Quote
We had the same problem on a 2001 International. I'm guessing your code is for the idle validation switch not agreeing with the tps or something along those lines. We ended up finding a wire rubbed through and intermittently making contact with the body in the dash; straight left of the driver's knee. I would suggest doing a wire wiggle test to see if you can duplicate it in the shop and go from there. Good luck! Those intermittent problems can be fun.
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Thomasbus24
Administrator

USA
4544 Posts

Posted - 03/21/2017 :  03:59:45 AM  Show Profile  Reply with Quote
A school I used to work for had the exact same issue as Dvorak describes, right down to the location, also a 2001 I believe. Another was rubbed in the doghouse area, but that was a DT.
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sob
Senior Member

USA
91 Posts

Posted - 03/21/2017 :  04:47:28 AM  Show Profile  Reply with Quote
I recall having a similar situation years back.

Try unhooking the Baro sensor. As I recall the Baro sensor shares the 5v reference signal with the APP. It was located under the dash between the Ign switch and the fuse panel.

Hope this helps, B
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krmvcs
Advanced Member

362 Posts

Posted - 03/21/2017 :  07:23:10 AM  Show Profile  Reply with Quote
i agree with Dvorak and Thomasbus24. same problem on gillig transit buses with the 466E. we usually just replaced the 50 or so feet of cable from the throttle to the ecm. seemed to be less time consuming than trying to find the worn wire. also double check the pins in the ECM connector.

-Ken-
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raytobe
Advanced Member

USA
293 Posts

Posted - 04/18/2017 :  03:37:53 AM  Show Profile  Visit raytobe's Homepage  Reply with Quote
quote:
Originally posted by krmvcs

i agree with Dvorak and Thomasbus24. same problem on gillig transit buses with the 466E. we usually just replaced the 50 or so feet of cable from the throttle to the ecm. seemed to be less time consuming than trying to find the worn wire. also double check the pins in the ECM connector.



I'm having the same problem on a 04 CE T444e although I can't find any rubbing wires and I can't duplicate the intermittent problem by wiggle tests. I'm thinking of replacing the wires also. How did you replace the twisted pair data wire Ken? Is a new pair sensitive to number of twists per inch etc.? Where did you get your pin ends for the ECU?

Edited by - raytobe on 04/18/2017 06:47:49 AM
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td83
Senior Member

83 Posts

Posted - 04/18/2017 :  04:57:11 AM  Show Profile  Visit td83's Homepage  Reply with Quote
Donguy have had the same issues numerous times on various busses with these dtcs one thing I have noticed is that the tps on the pedal should not be replaced by itself have had a couple comebacks when doing this the best way if tps is issue is to replace the pedal and tps as a unit and it will come mounted on the pedal ,*** I know this sounds crazy*** but check the resting voltage on service maxx should be around .45volts but with the tps just replaced by itself Ive found it reads .60 volts and will cause intermittent throttle response issue along with codes . I had 2 busses same dtcs and one kept having issues even right afer replacement of tps another tech advised me of this we scoped the tps s and found the discrepancy between the pedal unit and just the tps being replaced and on both this resolved the issue .again I know this souns like nonsense but if your wires check ok go for this and check the resting voltage before and after hope this helps, oh and the voltage differences were around .2 not 100% on the exact readings in service maxx but I think it was .45 and .60 something . One of the busses this kept happening on I got it on the 3rd time in for it but would only happen once a month was very intermittent the other bus would happen numerous times a day but after I was told about the pedal/tps I haven't had an issue since I started replacing them this way .

Edited by - td83 on 04/18/2017 05:50:20 AM
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krmvcs
Advanced Member

362 Posts

Posted - 04/18/2017 :  07:15:36 AM  Show Profile  Reply with Quote
quote:
Originally posted by raytobe

quote:
Originally posted by krmvcs

i agree with Dvorak and Thomasbus24. same problem on gillig transit buses with the 466E. we usually just replaced the 50 or so feet of cable from the throttle to the ecm. seemed to be less time consuming than trying to find the worn wire. also double check the pins in the ECM connector.



I'm having the same problem on a 04 CE T444e although I can't find any rubbing wires and I can't duplicate the intermittent problem by wiggle tests. I'm thinking of replacing the wires also. How did you replace the twisted pair data wire Ken? Is a new pair sensitive to number of twists per inch etc.? Where did you get your pin ends for the ECU?


Not sure about replacing the pins on the ECU. Ive never opened one up for surgery, just replaced it when the pins get burned or corroded. The connector end isnt bad but I couldnt tell you what the part number is or the crimper tool for them. This was when I was at the transit and we had part guys for this along with providing the proper type of bulk 2 wire shielded cable for the throttle to the engine. Sorry I cant be more helpful.

-Ken-
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eddo
Advanced Member

USA
311 Posts

Posted - 04/18/2017 :  11:35:26 AM  Show Profile  Reply with Quote
I don't remember if I had the same codes or not- but my TPS non responsive issue ended up being a rubbed through wire on the Neutral safety switch. One of the wires shared a common feed.
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raytobe
Advanced Member

USA
293 Posts

Posted - 04/18/2017 :  2:12:25 PM  Show Profile  Visit raytobe's Homepage  Reply with Quote


[/quote]
Not sure about replacing the pins on the ECU. Ive never opened one up for surgery, just replaced it when the pins get burned or corroded. The connector end isnt bad but I couldnt tell you what the part number is or the crimper tool for them. This was when I was at the transit and we had part guys for this along with providing the proper type of bulk 2 wire shielded cable for the throttle to the engine. Sorry I cant be more helpful.
[/quote]

Ok, Thanks. The pins on the connector were the ones I was talking about. Funny, I've had the connector plug off and on so many times that the bolt that holds the plug on the ECU wouldn't come off, it would just spin. I had to grind/drill the head to get the plug off. Then I had to take the ECU apart and epoxy the nut that the bolt threads into. Should be alright if I'm real gentle whenever I have to remove the plug.
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