I have been three weeks with my "out of warranty truck" and finally gonna have to give it to the dealer to look at. I wanted to know if this is a common problem, so here it goes...

I bought my 2007 5.9L used from a previous owner 6 mo. ago w/ only 27000 miles on the truck about 6 months ago(currently the truck has 31000 miles). When I bought it I noticed that the truck would turn the "ck engine" and after a few cycles of the ignition, it would go away. At that time, I did notice loss of accelerator pedal in reverse (it would not respond). I took it to a dealer and they could not pinpoint a problem. At the time their recommendation was to ignore the light. I was ok as long as they stated it was not a major problem.

Approximately 2 mo. later the problem got worse, while I was driving down the highway it started to loose accelerator control(no accelerator), hunting gears at 45-55 mph range and when I would be driving at 55 and start to lift the accelerator pedal to coast it would almost instantly start to downshift causing me to have to accelerate to maimtain speed. Now it con't with these symptoms and also won't shift past 2 at times, other times take too long to change gears when accelerating...(I have to pump the accelerator to change trans response to shift gears). Initially I took it to a friend that works on transmissions, since the dealers had been so helpful, I wanted a second opinion. He found the TPS sensor code and a cam sensor code, no transmission code nor anything wrong with the transmission mechanical. Both were changed but only the cam sensor code erased. Incidentally, the truck started to turn the alarm on out of the blue when shifting into reverse now (not always but often). Not sure if this was related to changing the sensors as this had happened to me once before.

So I took it to another friend of mine who is a diesel mechanic for heavy machinery, familiar w/ cummins and yesterday we ran through the circuits from the TPS or APPS to the computer plug on the engine and all were fine (using a voltmeter). The pins 1 and 6 are supponsed to maintain a constant 5v to the accelerator pedal, and we noticed that the current to the 6th pin would go dead when it was shifted to reverse. This was the only thing that was found at the time. No way to resolve or test further as our only tools were a scanner and an electrical meter. Resistances in the other pins appeared to be fine.

SO I am stuck right now with my truck that at times when I shift in reverse, the alarm goes off or the accelerator pedal won't respond. And on the road when going forward, hunts for gears, downshifts instead of coasting and sometimes will take tooo long to shift up in gears at times, and other times it shifts normal

I've been beaten down, my truck seems to not follow any particular symptom I have read, they are all symptoms I have seen posted,except the reverse-alarm relation, but they seem to resolve w/ changing the Trottle pedal or some other sensor.

The error codes that persist are:
P0698 Sensor Reference Voltage 3 Circuit Low
P2121 Pedal Position Sensor 1 Performance / Rationality
P2122 Pedal Position Sensor 1 Low

Can anyone suggest the possible cause of the problem? remember that the Pedal was replaced as well and currently is new and still I get these codes. and I still have the alarm turning on when I shift to reverse.

Any help is greatly appreciated. I'm taking it to the dealer soon, but would like to have insight as to what it may be.... CPU maybe?

havy

 

First off you have a 5 year 100k mile warranty. If they looked at it once under warranty and didn't fix it IT IS still covered because it's an ongoing issue. Did you clean your battery connections yet? These trucks do wierd things when the grounds are corroded!
Keep us posted on progress! Changing a sensor is easy finding a problem is a little harder. They get paid well make them earn their pay!

 

Whats the APPS/TPS PID doing when the failure occurs?
Sounds like a typical electrical control system failure, happens every day to thousands of vehicles . If your dealer cant find anything wrong, I'd take it do a better dealer. Again, sounds like problems techs fix every day all around the world !

 

Not really worried so much about the warrenty as I am about getting this thing on it's toes again... The previous owner had the Banks sixshooter system on it. He sold me the truck w/ all the intake and exuast mods, just no banks comp that came in the palm tungston computer. So I bought an Adrenalin that we installed. At the moment of testing and in the past chk-ups the comp has been totally disconnected. (BTW: don't race, its a DD and don't even tow, just love the response, almost like driving a sports car but I'm in a big'ole Truck! Love that)

... so as long as there is a remedy. I even thought of just buying a whole new engine comp and putting it in, but my friend explained that if the prob is in the trans comp then I would have wasted my money and it would be best if it was scanned at the dealer.
@ mysterync: thanks for the response, not sure about what is the PID? I'm just a friend to the mechanic and still need to be walked through. What I wrote is what I learned yesterday while working with him and that's what I wrote. Maybe if I knew what the PID was then I could clear that up.

Thanks for the responses,
havy

 

Parameter ID, So by asking you what the pid is doing, I'm asking for the data produced by the Sensor either in voltage or a computed number.
I can assure you that without properly diagnosing your truck , buying parts is only going to cost you money, You might get it right the first time, or the fifth time. You would only be guessing and thats pretty silly considering we have the knowledge and technology to properly diagnose vehicles these days. Although it does sound familiar to a failed ECM but it could still be a failed plug or damaged wire. All of your codes are associated with the 698 low voltage code, which means the power wire for the apps sensor is below 5 volts or shorted out, I would start there by testing the apps power wire , So if your looking at the apps plug with the clip up, on the far right is pin 6, On the ecm side its pin 54. Verify that wire is good and follow the procedure below! We know that the Reverse causes 5V to drop on pin 6, so If thats the case whats our common point between the two? We must check the wire on both ends to verify it's not a mechanical interference first.

Lets do this, Any good tech must start with the data

P0698-ACCELERATOR PEDAL POSITION SENSOR (APPS) SUPPLY VOLTAGE TOO LOW

* When Monitored:

With engine running.

* Set Condition:

Low voltage detected at the APPS supply circuit or low voltage detected at the APPS 1 5-volt supply.




Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.

1. (F855) 5-VOLT SUPPLY CIRCUIT SHORTED TO BATTERY NEGATIVE

Turn the ignition off.

Disconnect the ECM harness connectors.

Disconnect the APPS harness connector.

Check connectors - Clean/repair as necessary.

Measure the resistance of the APPS 1 (F855) 5-volt supply circuit between the sensor harness connector and battery negative

Is the resistance greater than 100 k ohms?

Yes

* Go To 2

No

* Repair the (F855) 5-volt supply circuit shorted to battery negative.


2. (F855) 5-VOLT SUPPLY CIRCUIT SHORTED TO OTHER CIRCUITS
Measure the resistance between the (F855) APPS 1 5-volt supply circuit at the ECM harness connector and all other circuits in the ECM connector.

Is the resistance greater than 100k ohms?

Yes

* Go To 3

No

* Repair the APPS #1 (F855) 5-volt supply circuit shorted to other circuits.


3. INTERNAL ECM

Reconnect the ECM harness connectors.

Turn ignition on, engine off.

While monitoring with the scan tool, connect a jumper wire between the (K23) APPS 1 signal circuit at the sensor harness connector and the (F855) APPS 1 supply circuit at the sensor harness connector.

NOTE: With the APPS disconnected it is normal to have a APPS 1 and APPS 2 low voltage DTC set.

Did a APPS 1 voltage too high DTC set?

Yes

* Go To 4

No

* Replace and program the ECM.


4. APPS

Reconnect the APPS harness connector.

Ignition on, engine not running.

Monitor the APPS 1 and APPS 2 voltage with the scan tool while depressing the throttle pedal.

Is the voltage transition shown on the scan tool smooth while depressing the throttle and is the volt swing smooth?

Yes

* Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
No

* Replace the APPS.

---AutoMerged DoublePost---

Have you tested your range sensor on the transmission? I would unpin T826 and see if the problem stops. It would be pin 9, looking at the Transmission range sensor plug, clip up, it would be on the bottom row, second over from the right.

 

Thanks for the follow-up. So this is pretty simple to diagnose... the scanner we had didn't give us voltage readouts on the channels, we did test the resistance to the other pins including pin # 1. We took out the ECU plugs and went through each channel. the continuity was good and the resistance I believe was good to.

Do you have a certain scanner you could recommend for future references/use? This it seems is the most important tool for me to have.

thankyou for your help.
havy

 

If you have a laptop auto ingenuity is probably the most realistic pricing wise, snap on has some good products, there is also a otc for about 370

 

I saw autoinguneity and ordered it with the expansion for my diesel truck. Thank you. I think I'm going to hold off on the dealer until I get this thing and sit down with my friend. Hopefully this will help me pinpoint the prob this time and in the future should be good to have.

Thanks again!

havy

 

I just wanted to give some feedback on what had happened... They discoverded that the prob was due to 2 wires that were left loose and rubbing caused them to expose. Then these wires shorted one of the engine computers and the trans comp. Also they changed something else in the trans, throttle body or shift body or something like that.

So nearly a mo later... Got my truck back.

Running this thing w/ a Banks six shooter intake and exuast system and an Adrenalin Iquad. Yeap, still love my truck, now just a little more.

I have one last question, given the mods this truck has, I run it on #Nine out of 10 settings. It has the best fuel consumption to power at this level. Just curious, will the stock trans hold up like this? And if i put in a new fuel pump/ filter (airdog,etc) and some 50hp injectors.

Thanks for everyones help.
Havy