burndiesel

I have an old, never resolved, cruise control problem, and a recent intermittent engine stumble/miss problem that both point to a Throttle Position Sensor TPS (APPS) failure. BUT, the TPS was replace twice within a couple days in 2012, and never did fix the Cruise Control problem, SO I think there is something else going wrong, but why the Cruise Control problem would be consistent and the engine stumble/miss is intermittent has me baffled….HELP!
I have ordered a new TPS from TMB Mechanical Service & Repair to have on hand to hand when this is dug into. Of note, truck is always in use with a trailer, often heavy. VP 44 injection pump replaced NOV 2011. The speed sensor camshaft (5080577AB) replaced JAN 2012.
Below is an explanation. Sorry for the length, but don’t know how else to explain:

CURRENT CRUISE CONTROL PROBLEM
-place CC on, 5/10 minutes later, engine check light on (ECL), CC turned off, truck drives normally.

-after driving with CC off and ECL on for an additional 5/10 minutes, the power will suddenly go to idle and the throttle in dead or non-responsive.

-pull over, turn truck off, wait a couple minutes (although I do not think waiting is even necessary), truck is restarted and throttle operates normally. ECL eventually extinguishes.

-codes that pull up when cycle ignition switch 3 times (code descriptions pulled from internet site):
P PCU
P 0500 VEHICLE SPEED SENSOR MALFUNCTION
P 1693 TURBO CHARGE CONTROL CIRCUIT MALFUCTION
P DONE
P ECU
P 1693
P 0122 THROTTLE POSITION SENSOR/SWITCH A CIRCUIT LOW INPUT
P 0121 THROTTLE POSITION SESOR/SWITCH A CIRCUIT RANGE/PERFORMANCE PROBLEM
P 0216 INJECTION TIMING CONTROL CIRCUIT MALFUNCTION
P 0234 ENGINE OVERBOOST CONDITION

-above scenario will happen like clockwork every time attempting to use CC.

HISTORY OF CRUISE CONTROL ISSUE
-SPT 2012 the dead throttle position above after using the CC did not correct with turning the truck off then on.
-dealership in Nebraska replaced the TPS (53031576AD LEVER-ACCELERATOR AND CRUISE $719!!)

-continuing the road trip, the same CC problem reoccurred within hours, BUT the dead throttle (non-responsive accelerator) was corrected by shutting the truck off then back on, and the truck operated normally without using the CC

-1 day later stopped at a dealership on Michigan and the TPS was again replaced as it was claimed that the one installed by the Dealership in Nebraska was faulty. The throttle cable was also replaced.

-attempted to use the CC again and the same problem occurred, but again, luckily, the non-responsive accelerator was corrected by turning the truck off then on.

-not using the CC has been my solution for the last 2 years. After the engine stumble/miss problem starting occurring (explained next), I tried using the CC in diagnosing the problem and the problem explained above is the current status.

ENGINE STUMBLE OR MISS AT OPERATING SPEEDS
-after truck in driving for over an hour, the engine starts to stumble or miss. It is an intermittent problem. Sometimes it will not do it for a couple days than starts doing it again. And sometimes the problem is more pronounced. Once it starts with the problem it seems to act that way fairly consistently for as long as the truck is running. If the truck is stopped for a short period (to get fuel for example) the problem will reoccur immediately. Not until the truck is turned off for a long time (overnight) will the problem reset, and it may or may not return after an hour or 2 of driving.

-twice on recent road trip the problem seemed to become more pronounced and the engine check light came on and the engine went to idle the same as with the CC problem. And as with the current CC problem the non-responsive throttle was corrected with shutting the truck off then on. BUT for the final 2 days of the trip the engine stumble problem did not reoccur.

-the problem can be heard and felt. Also, indicated on my boost gauge as the needle jumps around with a steady throttle foot position. The engine acts as if the accelerator is being sporadically pumped and/or your foot is allowed to abruptly slip off the accelerator.

-codes after engine stumble/miss that turned on ECL and non-responsive throttle:
P PCU
P 1693
P DONE
P ECU
P 0122
P 0216
P 0234
P DONE

-After the engine stumble/miss caused the ECL and non-responsive throttle, I did not clear the codes. Not until almost home did I turn on the CC to verify that that problem still existed from 2 years ago! So do not know which of the first codes also apply the CC problem. The codes that where new after testing the CC, are presumable only associated with it.
-With researching on line, and all the issues that come up associated with the TPS, there were a few cases where replacing the TPS did not resolve the problem, as was the case in my situation 2 years ago when the CC first occurred. The 0122 code (low voltage) and intermittent nature of the problem, was discussed as the possibility of a faulty wiring or connectivity issue. BUT the CC problem is not intermittent????

-Also, the common component in the CC/ Engine Stumble problem is the TPS, BUT it was replaces 2 years ago and didn’t fix the CC problem. To Clarify the Engine Stumble started approx. 6 months ago.

-there is a TPS (APPS) reset procedure that did fix some of the posted problems….?

2001 3500 4X4 6 Speed Manual
Fass Titanium Lift Pump with low fuel press light
AFE dry Filter air intake
Firestone AirBags
PACBRAKE first gen exhaust brake
NO CHIP
MAG-HYTEC diff cover
Autometer pillar triple gauge pack

AlpineRAM

Just some thoughts and guesses-

You seem to have at least 2 different problems going on at the same time.
A flaky vehicle speed sensor that kicks you out of cruise (for understandable safety reasons any error in the vehicle speed sensing disables the little robot mashing the go pedal for you)

And something that looks like a ground fault or a dying VP44.
The VP44 when not achieving the timing advance desired will give a code and retarded timing leads to higher boost due to high EGTs.

If all the stuff concerning vehicle speed and boost and both TPS faults get tripped at the same moment I would think of either a ground fault or a +5V supply fault in the PCM.

HTH

AlpineRAM

torquefan

The first thing I would do would be to erase all the faults, then see what comes back with each occurrence of the condition. Hopefully something will be a consistent clue instead of that list of faults that are already in there. I'm having trouble understanding how a condition like you describe could generate APPS faults and an injection timing fault (P0216) simultaneously. I would expect to see either one of those faults generated by that condition, but not both together.

An intermittent fault with the 5 volt supply circuit is also quite possible and can disrupt several sensors at the same time. I wouldn't immediately blame the PCM, but any sensor or its wiring can intermittently short and cause that.

burndiesel

Thanks for all the great input AlpineRAM and torquefan. When it is finally resolved I will report back!

AlpineRAM

As torquefan said- start with claring codes so that you don't get confused by old stuff.

Then drive a short distance, check for codes- rinse and repeat until code(s) start showing up.
Take note under which circumstances the truck throws the code- hot or cold, wet or dry etc.

In my experience this is the most efficient way to diagnose the more complex faults on any vehicle.

HTH

AlpineRAM

burndiesel

Thanks, I need to Clarify codes.

Forgot to mention:

in diagnosing the Engine Stumble problem, while the truck was experiencing the Engine stumble/miss I would engage the Cruise Control. As soon as the C C was engaged the engine stumble would go away! C C off, Engine Stumble would come right back. I would not leave the C C on very very long, as I did not want the C C dead pedal problem to happen.

-What I don’t understand is, the common component in the CC/ Engine Stumble problem is the TPS, BUT it was replaces 2 years ago and didn’t fix the CC problem. To Clarify the Engine Stumble started approx. 6 months ago. And why would the C C problem occur consistently, yet the Engine stumble is intermittent?

-This is a late 2001 truck with one cable running to the TPS, hence the C C is controlled by the ECM? Would this mean that there is strong possibility of a problem with the ECM and/or wiring to the ECM? With the intermittent nature of the engine stumble, and the fact that it takes an hour or 2 for it to occur (things to heat up), problem with the ECM not surprise me.

Depending what happens with erasing and checking new codes, I would consider sending the ECM and PCM in to be tested and have the components replaced that are prone to break down. SIA Electronis in Illinois seems like the best option from what I have researched?

high bid

I chased a very Similiar described problem for 6+ months. The electronic board in the vp44 can and WILL act up on an intermittent basis. In my opinion, I would check/ clean all grounds, reset TPS and drive. If problem still exists, replace IP.