Wondering if somebody can confirm these numbers are correct?

All tests are with the key on engine off

5 Volt Reference - harness disconnected from APP

D - TAN wire = 2.94 volts
E - YELLOW/BLACK wire = 2.94 volts
G - WHITE/BLACK wire = 4.94 volts

Harness connected to APP checking for SIGNAL

C - LIGHT BLUE = .52 closed throttle .13 WOT
F - DARK BLUE = .04 closed throttle .20 WOT
K - DARK GREEN = .20 closed throttle .09 WOT

C, F, and K do not sound right. I will check into it and get back.

But for example the starting voltage should be say 2.94v and increase to 4.50v as the pedal is pressed or the voltage should decrease depending which APP circuit that is being checked.

What I did was test the Signal lines by probing the appropriate connectors, in this case, C, F and K being the signal lines, and started the readings with the fuel pedal closed and then wide open.

Signal lines C,F and K did not seem right to me nor does Reference line G compared to D and E

I did not depress the fuel pedal while probing D,E and G as I was just checking for reference with the clip disconnected from the fuel pedal. With the clip being disconnected from the fuel pedal, should the 5-volt reference be the same throughout all 3 reference lines?

I will try D, E and G again with the clip connected and at WOT and post the results.

Voltage does not move through G, D or E when the clip is connected and pedal is at WOT. Voltage remains the same. It only changes through C, F and K Signal lines.

I will take a look when I get home later and post it for you. I am at work and do not have the info. I actually just went through this with my truck but do not remember the details and do not want to give you wrong info.

When I did this I did not have all the details I needed and thought I had the problem nailed down. Now I have an extra APP!:D

With the Key on: Between terminals G and A, D and B, E and J should all have 5 volts.

Between terminals F and A should have 0.5 volts and should increase and decrease as the pedal is pressed and released.

Between terminals C and B should have 4.5 volts and should decrease and increase as the pedal is pressed and released.

Between terminals K and J should have 4.0 volts and should decrease and increase as the pedal is pressed and released.

The test can also be done by using ohms and the connector unplugged.

ABarnaby,

Thank you for testing this out for me. Are you testing the G & A, D & B connectors together or individually. I tested my terminals individually. I used the black prong as it's own ground on the chasis and used the red line in the terminals to determine my readings.

ABarnaby,

Thank you for testing this out for me. Are you testing the G & A, D & B connectors together or individually. I tested my terminals individually. I used the black prong as it's own ground on the chasis and used the red line in the terminals to determine my readings.

When you test put one lead In G and the other in A and you should get the 5.0 volts. Then put one lead in D and the other in B and again 5.0 volts. You should not use the chasis as the ground because you are testing the circuit back to the PCM so use A with G and D with B and E with J.

If you have the polarity wrong your meter will read a negative #.

I did a few tests with it grounded to chasis and as you described and the readings are the same either way. Either I am reading this wrong or my APP is faulty.

Everyone is pointing to the IP but I still believe it is the APP.

With you having a working APP and having readings that seem to make sense and my readings all over the map, I think we may have pin pointed the issue.

I truly appreciate your respnse and time into this matter ABarnaby


Would be nice if someone else could also confirm ABarnaby's readings are indeed accurate. Mine seem wanky for sure

I did a few tests with it grounded to chasis and as you described and the readings are the same either way. Either I am reading this wrong or my APP is faulty.

Everyone is pointing to the IP but I still believe it is the APP.

With you having a working APP and having readings that seem to make sense and my readings all over the map, I think we may have pin pointed the issue.

I truly appreciate your respnse and time into this matter ABarnaby

I have an extra if you are in need. You can PM me.

I guess my last question would be why am I not getting 5 volts to the D and E terminals as these really have nothing to do with the pedal when they are disconnected. They should be feeding 5 volts at all times with Key on Engine off.

Also, my readings appear to be low yet I am setting a DTC 25 - Accelerator Pedal Position 2 Circuit High

I am confused by this whole APP let me tell you

You should check the Voltage at the PCM to see if it is puting out 5v. If you do not have the 5V on D and E it could be the PCM. Just be sure no wires are shorted or open.

You should not use the chasis as the ground because you are testing the circuit back to the PCM so use A with G and D with B and E with J.



I did a few tests with it grounded to chasis and as you described and the readings are the same either way. Either I am reading this wrong or my APP is faulty.




Im confused he said NOT use chassis ground and then you said you did, are you sure you did it right or is this just a mistype?

I tried both ways, Using the wires and grounding and the readings come back the same.....These APP pedal are very intricut

So I thought for shits and giggles I would try a different volt meter just in case my older one was wanky, surprisingly, I came up with different results


Terminals G and A have 5.03 Volts and do not fluctuate at all when pedal is at WOT

Terminals D and B have 5.03 Volts and do not fluctuate at all when pedal is at WOT

Terminals E and J have 4.90 Volts and can drop down in volts to 0.64 when pedal is at WOT

Between terminals F and A have 0.66 volts and increase to 3.44 volts

Between terminals C and B have 4.40 volts and decrease to 1.72 volts

Between terminals K and J have 3.38 volts and decrease ro 0.62 volts

All above tests are as ABarnaby had tested and these were the results. I think this is pointing to a bad APP for sure. I would like to try another APP in place of mine and see what happens before I spend over $400.00 for a new one.

I seem to be getting a higher voltage than what is required through terminals G and A and D and B which is what could be setting my DTC-25

I am getting a continuous 5.03 volts through these terminals which is either a short somehere along the lines or a bad PCM as it is sending the wrong signals

So we know that the APP has 3 sensors, my readings throughout APP sensor 1 appear to be correct, it is APP sensors 2 and 3 where the problem seems to be but I am not sure if it is the pedal or the wiring

Incase some are wondering what signal wirings are what

G, F and A are all in Sensor circuit 1

D, B and C are all in Sensor circuit 2

E, J and K are all in Sensor circuit 3

Was the APP for 94+ 6.5s only or were there other applications? (for junk yard hunting)

So I thought for shits and giggles I would try a different volt meter just in case my older one was wanky, surprisingly, I came up with different results


Terminals G and A have 5.03 Volts and do not fluctuate at all when pedal is at WOT

Terminals D and B have 5.03 Volts and do not fluctuate at all when pedal is at WOT

Terminals E and J have 4.90 Volts and can drop down in volts to 0.64 when pedal is at WOT

Between terminals F and A have 0.66 volts and increase to 3.44 volts

Between terminals C and B have 4.40 volts and decrease to 1.72 volts

Between terminals K and J have 3.38 volts and decrease ro 0.62 volts

All above tests are as ABarnaby had tested and these were the results. I think this is pointing to a bad APP for sure. I would like to try another APP in place of mine and see what happens before I spend over $400.00 for a new one.

I seem to be getting a higher voltage than what is required through terminals G and A and D and B which is what could be setting my DTC-25

I am getting a continuous 5.03 volts through these terminals which is either a short somehere along the lines or a bad PCM as it is sending the wrong signals

So we know that the APP has 3 sensors, my readings throughout APP sensor 1 appear to be correct, it is APP sensors 2 and 3 where the problem seems to be but I am not sure if it is the pedal or the wiring

Incase some are wondering what signal wirings are what

G, F and A are all in Sensor circuit 1

D, B and C are all in Sensor circuit 2

E, J and K are all in Sensor circuit 3

I do not think E and J should change when pedal is pressed. It is a reference voltage and I believe should be constant 5V. The other issue I see is E and J should be the same as G and A and D and B, these to are reference voltages.

Was the APP for 94+ 6.5s only or were there other applications? (for junk yard hunting)
I had no luck at the juck yard. The just do not have a lot of diesels in them.
It is a diesel application.

ABarnaby,

So what you are basically saying is I have a fault in Sensor Circuit 3

Is it ok that I am a tad over the 5 volt reference?



I found some info on the APP and it is as follows


APP Sensor Circuit 1 produces a varying voltage of between 0.35volts-0.95volts dc at idle and 4.0 volts dc at WOT

APP Sensor Circuit 2 produces a varying voltage of between 4.5 volts dc at idle and 1.0volts dc at WOT

APP Sensor Circuit 3 produces a varying voltage of between 4.1 volts dc at idle and 2.5 volts dc WOT


If I compare the information based on the above readings to what I have recorded, I think we have diagnosed a faulty APP as the readings in APP Sensor Circuit 3 are way out. APP Sensor Circuit 1 and 2 are within specs....

Please confirm this if you believe what I am reading is correct.....

ABarnaby,

So what you are basically saying is I have a fault in Sensor Circuit 3

Is it ok that I am a tad over the 5 volt reference?



I found some info on the APP and it is as follows


APP Sensor Circuit 1 produces a varying voltage of between 0.35volts-0.95volts dc at idle and 4.0 volts dc at WOT

APP Sensor Circuit 2 produces a varying voltage of between 4.5 volts dc at idle and 1.0volts dc at WOT

APP Sensor Circuit 3 produces a varying voltage of between 4.1 volts dc at idle and 2.5 volts dc WOT


If I compare the information based on the above readings to what I have recorded, I think we have diagnosed a faulty APP as the readings in APP Sensor Circuit 3 are way out. APP Sensor Circuit 1 and 2 are within specs....

Please confirm this if you believe what I am reading is correct.....

Yes, but I think I would verify the 5 volts from the PCM first. All these parts are pricey!!! All the reference volts should be the same.