sooty

got a 6 speed setting the tps dtc, along with p0148 fuel delivery error, 6 months ago, replaced the cable operated tps, under driver side battery, still having rough running problems, exiting the freeway, on decel, it will stall, on restart, will stagger, not responding to pedal activity, scanner previously showed no tps activity, intermittantly, on restart it will recover, or continue staggering. got a long road trip coming up, need this problem gone, any similarities, or comparisons with other trucks?

rip 112

Ive had a similar issue, but when it happens to me i get no codes, the pedal goes dead and the truck will coast to a stop and die. It will take at least 3 attempts starting it before it will fire back up. When it does crank and run you wouldn't even know anything was wrong, truck runs fine and everything checks out. On occasion instead of the truck and pedal dying, while driving the truck will start surging (extreme, like fuel off, fuel on). When I pull over the truck will lope. Funny thing is when It last happened (4 months ago) the solution came when I turned the ac/ heater off.


I have heard of a wiring issue close to the ac wiring on the front of the motor. I wish I knew the details, but this discussion was a couple of yrs ago, maybe someone can chime up.

sooty

does anyone have a flow chart for this dtc?

madhat

Symptom:
P2121-APP VOLTS DO NOT AGREE WITH IDLE VALIDATION SIGNAL
When Monitored and Set Condition:
P2121-APP VOLTS DO NOT AGREE WITH IDLE VALIDATION SIGNAL
When Monitored: While the engine is running.
Set Condition: IVS indicates idle whileAPPS signal voltage indicates not at idle condition
or IVS indicates not at idle while APPS signal voltage indicates idle condition.
POSSIBLE CAUSES
OTHER APPS DTC’S
APPS
(K851) 5-VOLT SUPPLY SHORTED TO VOLTAGE
(K22) SIGNAL CIRCUIT SHORTED TO (K556) NOT IDLE CIRCUIT
ECM
(K851) 5-VOLT SUPPLY CIRCUIT IN ECM
INTERMITTENT CONDITION
APPS
INTERMITTENT CONDITION
TEST ACTION APPLICABILITY
1 Using the DRBIIIt, check for any other APPS DTC’s.
Are any other APPS DTC’s present?
All
Yes ! Repair other APPS DTC’s first.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).
No ! Go To 2
2 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 3
No ! Go To 8
3 Turn the ignition off.
Disconnect the APPS harness connector.
NOTE: Check connectors - Clean/repair as necessary.
Measure the resistance between the (K22) signal circuit at the sensor and the (K556)
not idle circuit at the sensor.
Is the resistance less than 10 ohms?
All
Yes ! Replace the APPS.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).
No ! Go To 4
4 Disconnect the ECM harness connectors.
NOTE: Check connectors - Clean/repair as necessary.
Measure the voltage between the (K851) 5-volt supply circuit of the sensor harness
connector and battery negative.
Is the voltage greater than 1 volt?
All
Yes ! Repair or replace the (K851) 5-volt supply circuit shorted to
voltage.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).
No ! Go To 5
5 Measure the resistance between the (K22) signal circuit of the sensor harness
connector and (K556) not idle Circuit of 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 6
6 Reconnect the ECM harness connectors.
Measure the resistance between the (K22) signal circuit of the sensor harness
connector and (K556) not idle circuit of the sensor harness connector.
Is the resistance less than 10 ohms?
All
Yes ! Replace and program the ECM in accordance with the Service
Information.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).
No ! Go To 7
7 Turn the ignition on.
Measure the voltage of the (K851) 5-volt supply circuit at the sensor harness
connector and battery negative.
Is the voltage greater than 5.5 volts?
All
Yes ! Replace and program the ECM in accordance with the Service
Information.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).
No ! Refer to the INTERMITTENT CONDITION Symptom (Diagnostic
Procedure).
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).
8 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).

BigIron70

Inspect the engine to body ground strap located between the left rear of the cylinder head and the left side of the bulk head for wire harness contact.
Also check the 14-way connectors at the clutch / transmission bell housing. Check for oil coming from the transfer case vent which may be getting onto the 14-way connectors.

JJPage

Here is a link to that post, boy, I had to dig!

https://www.dieseltruckresource.com/...6.html?t=81936

rip 112

Thanks man!!!