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Measure the resistance between pin
4 and 10
3 and 8
1 and 7
Measure the resistance between pin
5 and 10
9 and 8
6 and 1
Measure the resistance between pin
5 and 4
9 and 3
6 and 7


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Discussion Starter · #222 ·
Measure the resistance between pin
4 and 10
3 and 8
1 and 7
Measure the resistance between pin
5 and 10
9 and 8
6 and 1
Measure the resistance between pin
5 and 4
9 and 3
6 and 7


View attachment 123917
I tested both the new one that is installed and the old original one:
Testing the APS
Measure the resistance between pin
New Original
4 and 10 3.18 3.46
3 and 8 3.20 3.41
1 and 7 5.12 5.55
Measure the resistance between pin

5 and 10 3.88 4.48
9 and 8 .833 .692
6 and 1 1.195 .639
Measure the resistance between pin

5 and 4 1.38 1.019
9 and 3 3.39 4.10
6 and 7 1.195 .637
 

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Discussion Starter · #223 ·
I tested both the new one that is installed and the old original one:
Testing the APS
Measure the resistance between pin
New Original
4 and 10 3.18 3.46
3 and 8 3.20 3.41
1 and 7 5.12 5.55
Measure the resistance between pin

5 and 10 3.88 4.48
9 and 8 .833 .692
6 and 1 1.195 .639
Measure the resistance between pin

5 and 4 1.38 1.019
9 and 3 3.39 4.10
6 and 7 1.195 .637
That did come out the way I spaced it.
 

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With the accelerator pedal in the WOT ("wide open throttle ) position
Measure the resistance between pin
5 and 10
9 and 8
6 and 1
Measure the resistance between pin
5 and 4
9 and 3
6 and 7
 

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Discussion Starter · #225 ·
With the accelerator pedal in the WOT ("wide open throttle ) position
Measure the resistance between pin
5 and 10
9 and 8
6 and 1
Measure the resistance between pin
5 and 4
9 and 3
6 and 7
Measure the resistance between pin
5 and 10- 1.621
9 and 8- 3.09
6 and 1- 3.84
Measure the resistance between pin
5 and 4- 0L
9 and 3- 1.116
6 and 7- 2.60

I measured 5 and 4 three times and got 0L
 

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Measure the resistance between pins 5 and 6 starting with the pedal in the idle position, slowly depress the pedal to determine where the circuit becomes open circuit.
 

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Discussion Starter · #227 ·
Measure the resistance between pins 5 and 6 starting with the pedal in the idle position, slowly depress the pedal to determine where the circuit becomes open circuit.
I bolted the gas pedal assembly to a board and used tiny alligator clips for a secure contact so I could do this. I found no resistance at all between #'s 5&6. Are you sure you didn't mean 4 &5? On those, I finally got a reading of 1.38 and as I depressed the pedal, the reading increased until about half way I got a 0 reading. Then it continued increasing to 3.67 at full throttle.
 

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Discussion Starter · #228 ·
I bolted the gas pedal assembly to a board and used tiny alligator clips for a secure contact so I could do this. I found no resistance at all between #'s 5&6. Are you sure you didn't mean 4 &5? On those, I finally got a reading of 1.38 and as I depressed the pedal, the reading increased until about half way I got a 0 reading. Then it continued increasing to 3.67 at full throttle.
I want to add that I did my best to be sure the new APS I installed back in November was in the exact position as the original.
 

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4 and 5 were the correct pins to test, the test suggests there may be a problem with the sensor. I recommend you reinstall the original sensor and repeat all the testing. The original sensor produced numbers closer to OEM sensors I have measured than the installed aftermarket sensor.
 

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Discussion Starter · #230 ·
4 and 5 were the correct pins to test, the test suggests there may be a problem with the sensor. I recommend you reinstall the original sensor and repeat all the testing. The original sensor produced numbers closer to OEM sensors I have measured than the installed aftermarket sensor.
The original APS starts at 1.381 and goes to 0L about a third of the way and then increases to 4.03 at full throttle.
 

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Discussion Starter · #231 ·
The original APS starts at 1.381 and goes to 0L about a third of the way and then increases to 4.03 at full throttle.
Should I re-stall the gas pedal, and does that "flat spot" matter?
 

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What APS module is mounted to the pedal assembly, the original or aftermarket? I think the original APS is the one you should use for now.

What PCM is installed?
 

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Discussion Starter · #233 ·
What APS module is mounted to the pedal assembly, the original or aftermarket? I think the original APS is the one you should use for now.

What PCM is installed?
My last set of results are from the original APS and the PCM is the most recently purchased one.
The original APS starts at 1.381 and goes to 0L about a third of the way and then increases to 4.03 at full throttle. Again, is the "flat spot" 0L a problem? It comes up faster on the original APS as I press the pedal down.
 

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I don't think the flat spot is an issue on the original APS, the real issue is why the the throttle valve does not open and close in response to the accelerator position.
 

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Discussion Starter · #235 ·
I don't think the flat spot is an issue on the original APS, the real issue is why the the throttle valve does not open and close in response to the accelerator position.
Perhaps I should re-install the original TPS and throttle valve?
 

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I recommend you do that because it is not likely it is defective since you were driving the truck before you installed the antenna.
 

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Discussion Starter · #237 ·
I recommend you do that because it is not likely it is defective since you were driving the truck before you installed the antenna.
I installed the original APS and original TPS with the valve body. The Trooper still fires up and immediately shuts down. The throttle does not open. Here's another quirk. It will fire up and shut down in all throttle positions except full throttle. It will not fire up in full throttle. Then I checked the trouble codes and got the following:
Codes
1120 - Throttle motor position sensor 1 – circuit malfunction
1125 - P1125 – Accelerator Pedal Position Sensor Fault
1220 - Throttle Position (TP) Sensor 2 Circuit
1295 - Electronic Throttle System Limp Home
1299 – cylinder head overheating – bad sensor?
It is truly exasperating.
 

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When you crank a fuel injected engine the PCM disables the fuel injectors if the throttle is held wide open (WOT), this allows you to crank a fuel flooded engine without adding more fuel.

The next thing to troubleshoot is the Throttle Position Sensor (TPS).
DTC P1120 and DTC1220 indicate a problem with both TPS#1 and TPS#2.

iP1125 is Electric Throttle Control (ETC) Limit Performance Mode. When this is set the PCM is commanding a Forced Idle condition because there is a detected anomaly in the ETC. In this case, DTC P1120 and DTC1220.
P1299 is ETC Forced Engine Shutdown, which is likely caused by DTC P1120 and DTC1220.

Start troubleshooting the Throttle Position Sensor (TPS) by disconnecting the Throttle Body wiring harness connector from the TPS/Throttle Body connector.

Measure the resistance between wiring harness connector Pin 1 and Pin 4 to a good engine block ground.
Pin 1 is the ground for TPS#1
Pin 4 is the ground for TPS#2
The expected resistance is less than 1/2 ohm.
Rectangle Font Parallel Number Drawing
 

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Discussion Starter · #239 ·
When you crank a fuel injected engine the PCM disables the fuel injectors if the throttle is held wide open (WOT), this allows you to crank a fuel flooded engine without adding more fuel.

The next thing to troubleshoot is the Throttle Position Sensor (TPS).
DTC P1120 and DTC1220 indicate a problem with both TPS#1 and TPS#2.

iP1125 is Electric Throttle Control (ETC) Limit Performance Mode. When this is set the PCM is commanding a Forced Idle condition because there is a detected anomaly in the ETC. In this case, DTC P1120 and DTC1220.
P1299 is ETC Forced Engine Shutdown, which is likely caused by DTC P1120 and DTC1220.

Start troubleshooting the Throttle Position Sensor (TPS) by disconnecting the Throttle Body wiring harness connector from the TPS/Throttle Body connector.

Measure the resistance between wiring harness connector Pin 1 and Pin 4 to a good engine block ground.
Pin 1 is the ground for TPS#1
Pin 4 is the ground for TPS#2
The expected resistance is less than 1/2 ohm.
View attachment 123964
There was no resistance measure. I switched to the beep mode and got no beep either.
 

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To be clear, you'r measuring the side of Throttle body connector with the wires going into it and not on the throttle body?
 
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