My APPS deffinatly was bad. It wouldn't take off until I hit the gas 4 or 5 time's. And it had the 2121 and 2122 code's. But what was kinda strange is the truck was running really good once I got going. It seemed like it had alot of power, especially while towing my 3 car trailer. I just had the problem's on take off.

I changed the APPS assembly and reset everything. I noticed on the test drive it seemed to have less power, and really noticed less power while towing. One thing I did notice is the electrical value's on the new APPS was slightly higher than the old. I can't remember the exact #'s, but it was something like the old was .053, and the new is .057. Could that have anything to do with it. I called the dealer to confirm that I got the right part. He said there was only 1 for the stick, and one for the auto. And I had the right one.


When I installed the new part, I put a little "Bulb greese" on the prong's. I think I'll pull it all apart again and clean the connector's with some spray. Also, would a misadjusted throttle pressure cable cause the sensor to go bad. Any idea's. Thank's.

 

When I changed mine I had to unhook the negative bat. cables for a half hour & reconnect then press gas pedal slowly down/ up to reset the ecm.

 

I did that.

 

Is it going through the gears quicker and maybe that is why it seems to have less power? If so, then you would need to adjust the TV cable again...

 

Have you done this?
https://www.dieseltruckresource.com/...n&onlynewfaq=1

 

I doesn't seem to be going through the gear's any quicker. It just seem's to have a less power over all. But I know the tv cable needs adjusted. It's still over reving when it downshift's going up a hill. The guy at the trani shop told me not to mess with it. And since my last run technically put me out of warranty, I'm not going to. I'll let him do it Monday.


Will that work on a 3rd gen. Like I said above, the voltage rating was differant between the 2 sensor's. Wich one should it be set for I wonder.

 

Set it to the voltage on the back of the sensor.

 

Is it enough of a differance to matter. The old one was .585, and the new is .543. Would that be considered alot of differance. Also, should I wait until the trani guy put's the cable back to where it was. Thank's.

 

I hate to keep bugging you guy's, but I just want to get this right. Looking at the pic below, do I use pin 1 and 5 to test the voltage. Thank's.

 

This will at least tell you how to test the sensor.

Symptom:
P2122-LOW VOLTAGE AT THE APP SENSOR
When Monitored and Set Condition:
P2122-LOW VOLTAGE AT THE APP SENSOR
When Monitored: While the key is on and during engine operation.
Set Condition: The APPS circuit voltage at the ECM goes below 0.13 volt for more than
2 seconds.
POSSIBLE CAUSES
APPS
APPS
APPS
APPS
(K851) 5-VOLT SUPPLY CIRCUIT OPEN
(K22) SIGNAL CIRCUIT OPEN FROM ECM TO APPS
(K22) SIGNAL CIRCUIT SHORTED TO (K922) RETURN CIRCUIT
(K22) SIGNAL CIRCUIT SHORTED TO GROUND
(K22) SIGNAL CIRCUIT SHORTED TO (K914) SENSOR RETURN
(K851) 5-VOLT SUPPLY CIRCUIT SHORTED TO (K922) RETURN CIRCUIT
(K851) 5-VOLT SUPPLY CIRCUIT SHORTED TO (K914) SENSOR RETURN
(K851) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND
(K22) SIGNAL CIRCUIT SHORTED TO (K565) IDLE CIRCUIT
(K22) SIGNAL CIRCUIT SHORTED TO (K556) NOT IDLE CIRCUIT
ECM
INTERMITTENT CONDITION
(K23) APPS NO. 1 SIGNAL CIRCUIT OPEN
(K852) APPS NO. 1 5-VOLT SUPPLY OPEN
(K23) APPS NO. 1 SIGNAL CIRCUIT SHORTED TO GROUND
(K23) APPS NO. 1 SIGNAL CIRCUIT SHORTED TO OTHER CIRCUITS
(K852) APPS NO. 1 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND
(K852) APPS NO. 1 5-VOLT SUPPLY CIRCUIT SHORTED TO OTHER CIRCUITS
ECM
APPS
INTERMITTENT CONDITION
220
DRIVEABILITY - DIESEL
TEST ACTION APPLICABILITY
1 The diesel engine uses two types of throttle position sensors, depending on transmission
configuration.
Is the throttle position sensor is located on the engine?
All
Yes ! Go To 2
No ! Go To 17
2 Turn the ignition off.
Disconnect the APPS harness connector.
NOTE: Check connectors - Clean/repair as necessary.
Measure the resistance between the (K22) signal circuit of the sensor to the (K851)
5-volt supply circuit of the sensor.
Is the resistance between 1500 - 3000 Ohms with the accelerator pedal released?
All
Yes ! Go To 3
No ! Replace the APPS.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).
3 Measure the resistance between the (K22) signal circuit of the sensor to the (K851)
5-volt supply circuit of the sensor.
NOTE: Released resistance must be at least 1000 Ohms greater than depressed
resistance.
Is the resistance between 200 - 1500 Ohms with the accelerator pedal depressed?
All
Yes ! Go To 4
No ! Replace the APPS.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).
4 Measure the resistance between the (K851) 5-volt supply circuit of the sensor and the
(K922) return circuit of the sensor.
Is the resistance between 2000 and 3000 Ohms, depressed as well as released?
All
Yes ! Go To 5
No ! Replace the APPS.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).
5 Connect a jumper wire between the (K22) signal circuit in the sensor harness
connector and the (K851) 5-volt supply circuit in the sensor harness connector.
With the DRBIIIt, read DTCs.
Did P2123 set?
All
Yes ! Replace the APPS.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).
No ! Go To 6
221
DRIVEABILITY - DIESEL
P2122-LOW VOLTAGE AT THE APP SENSOR — Continued
TEST ACTION APPLICABILITY
6 Disconnect the ECM harness connectors.
NOTE: Check connectors - Clean/repair as necessary.
Measure the resistance of the (K851) 5-volt supply circuit between the APPS harness
connector and the ECM harness connector.
Is the resistance less than 10 ohms?
All
Yes ! Go To 7
No ! Repair the open (K851) 5-volt supply circuit.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).
7 Measure the resistance of the (K22) signal circuit between the APPS harness
connector and the ECM harness connector.
Is the resistance less than 10 ohms?
All
Yes ! Go To 8
No ! Repair the open (K22) signal circuit from ECM to APPS harness
connector.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).
8 Measure the resistance between the (K22) signal circuit in the sensor harness
connector and the (K922) return circuit in the sensor harness connector.
Is the resistance less than 10 ohms?
All
Yes ! Repair the (K22) signal circuit shorted to the (K922) return
circuit.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).
No ! Go To 9
9 Measure the resistance between the (K22) signal circuit in the sensor harness
connector and battery negative.
Is the resistance less than 10 ohms?
All
Yes ! Repair the (K22) signal circuit shorted to ground.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).
No ! Go To 10
10 Measure the resistance between the (K22) signal circuit in the sensor harness
connector and the (K914) sensor return circuit of the ECM harness connector.
Is the resistance less than 10 ohms?
All
Yes ! Repair the (K22) signal circuit shorted to the (K914) sensor return
circuit.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).
No ! Go To 11
222
DRIVEABILITY - DIESEL
P2122-LOW VOLTAGE AT THE APP SENSOR — Continued

 

TEST ACTION APPLICABILITY
11 Measure the resistance between the (K851) 5-volt supply circuit in the sensor
harness connector and the (K922) return circuit in the sensor harness connector.
Is the resistance less than 10 ohms?
All
Yes ! Repair the (K851) 5-volt supply circuit shorted to the (K922)
return circuit.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).
No ! Go To 12
12 Measure the resistance between the (K851) 5-volt supply circuit in the sensor
harness connector and battery negative.
Is the resistance less than 10 ohms?
All
Yes ! Repair the (K851) 5-volt supply circuit shorted to ground.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).
No ! Go To 13
13 Measure the resistance between the (K851) 5-volt supply circuit in the sensor
harness connector and the (K914) sensor return circuit of the ECM harness
connector.
Is the resistance less than 10 ohms?
All
Yes ! Repair the (K851) 5-volt supply circuit shorted to the (K914)
sensor return circuit.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).
No ! Go To 14
14 Measure the resistance between the (K22) signal circuit in the sensor harness
connector and the (K565) idle switch circuit in the sensor harness connector.
Is the resistance less than 10 ohms?
All
Yes ! Repair the (K22) signal circuit shorted to the (K565) idle circuit.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).
No ! Go To 15
15 Measure the resistance between the (K22) signal circuit in the sensor harness
connector and the (K556) not idle switch circuit in the sensor harness connector.
Is the resistance less than 10 ohms?
All
Yes ! Repair the (K22) signal circuit shorted to the (K556) not idle
circuit.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).
No ! Go To 16
223
DRIVEABILITY - DIESEL
P2122-LOW VOLTAGE AT THE APP SENSOR — Continued
TEST ACTION APPLICABILITY
16 Reconnect the ECM harness connectors.
Ignition on, engine not running.
Connect a jumper wire between the (K22) signal circuit in the sensor harness
connector and the (K851) 5-volt supply circuit in the sensor harness connector.
Did DTC P2123 set?
All
Yes ! Refer to the INTERMITTENT CONDITION Symptom (Diagnostic
Procedure).
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).
No ! Replace and program the ECM in accordance with the Service
Information.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).
17 Turn the ignition off.
Disconnect the ECM harness connectors.
Disconnect the APPS harness connector.
NOTE: Check connectors - Clean/repair as necessary.
Measure the resistance of the (K23) APPS No. 1 signal circuit between the APPS
sensor harness connector and the ECM harness connector.
Is the resistance less than 10 ohms?
All
Yes ! Go To 18
No ! Repair the (K23) APPS No. 1 signal circuit open.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).
18 Measure the resistance of the (K852) APPS No. 1 5-volt supply circuit between the
APPS sensor harness connector and the ECM harness connector.
Is the resistance less than 10 ohms?
All
Yes ! Go To 19
No ! Repair the (K852) APPS No. 1 5-volt supply open.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).
19 Measure the resistance between the (K23) APPS No. 1 signal circuit at the sensor
harness connector and battery negative.
Is the resistance greater than 100 k ohms?
All
Yes ! Go To 20
No ! Repair the (K23) APPS No. 1 signal circuit shorted to ground.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).
20 Measure the resistance between the (K23) APPS No. 1 signal circuit at the sensor
harness connector and all other circuits in the ECM harness connector.
Is the resistance greater than 100 k ohms?
All
Yes ! Go To 21
No ! Repair the (K23) APPS No. 1 signal circuit shorted to other
circuits.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).
224
DRIVEABILITY - DIESEL
P2122-LOW VOLTAGE AT THE APP SENSOR — Continued
TEST ACTION APPLICABILITY
21 Measure the resistance between the (K852) APPS No. 1 5-volt supply circuit at the
sensor harness connector and battery negative.
Is the resistance greater than 100 k ohms?
All
Yes ! Go To 22
No ! Repair the (K852) APPS No. 1 5-volt supply circuit shorted to
ground.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).
22 Measure the resistance between the (K852) APPS No. 1 5-volt supply circuit at the
sensor harness connector and all other circuits in the ECM harness connector.
Is the resistance greater than 100 k ohms?
All
Yes ! Go To 23
No ! Repair the (K852) APPS No. 1 5-volt supply circuit shorted to
other circuits.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).
23 Reconnect the ECM harness connectors.
Turn the ignition on.
While monitoring with the DRBIIIt, connect a jumper wire between the (K23) APPS
No. 1 signal circuit at the sensor harness connector and the (K852) APPS No. 1 5-volt
supply circuit at the sensor harness connector.
NOTE:With the sensor disconnected it is normal to have aAPPS 1 andAPPS
2 low voltage DTC set.
Did DTC P2123 set?
All
Yes ! Go To 24
No ! Replace and program the ECM in accordance with the Service
Information.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).
24 Reconnect the APPS harness connector.
Monitor the APPS 1 and APPS 2 voltage with the DRBIIIt while depressing the
throttle pedal.
Is the voltage transition shown on the DRBIIIt smooth while depressing the throttle
and is the volta
All
Yes ! Refer to the INTERMITTENT CONDITION Symptom (Diagnostic
Procedure).
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).
No ! Replace the APPS.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).
225
DRIVEABILITY - DIESEL
P2122-LOW VOLTAGE AT THE APP SENSOR — Continued

 

Wow. That's what I call a reply. That will keep me buisy for a while. Thank's for taking the time to post it.

I've read where several guy's are still adjusting them, even though they're suppossed to be set. What concerns me is the voltage rating between the new and old part are differant. In you're opion, should I try adjusting it, or leave it alone. Thank's.

 

The differnce between the new and old is expected since no two APPS sensors are the same. What your doing as making sure the computer is getting the correct position data from the sensor. If it is off, the truck will not fuel right. Say on the old sensor, part throttle was 50k ohm (not accurate by any means), but on the new sensor, the same peddle position was 80k ohm. The computer would apply fuel base on that number. So, by adjusting the sensor to the correct setting, you are insuring that the computer is getting accurate part throttle readings.

Look at it like replacing inner and outer tie rods on your truck. You wouldn't just put them on without adjusting them. If you did, the steering response would not be accurate.

 

I would say leave it alone. The ecm will determine what is the low setting vs. the high setting and make the necessary adjustments. The voltage is just a reference point. If yo uunhook the batteries and then do a "sweep" of the apps. that will basically force the ecm to relearn the min. max. voltages.