Hi I have a 04 Camry and have a p2121 code TPS /apps sensor problem I wonder how u can nail down with parts is wrong or how to fix the problem?

2001 6.0L engine. Suburban? 2500HD
the coolant must be full, no air pockets that cause ETC sensor to lie.
and chev, love to self protect the engine at overfheating
or the ECT telling lies , AIR pocket there = lies.
my scan tool I can watch the ECT full time. even graph it.
all I have are questions, things I see in person fast.
IMMO lamp glowing wrong on dash, IMMOBIlizer? ?????
if yes it cuts the engine is 3 to 10 seconds. by design.
seem spark is good and only fuel wrong is fuel pressure at spec?
or is AIR wrong, all engines must have air to start, or stalls.
air comes 2 ways (old to newer) IAC/ISC or TWB (GM TAC)
TAC IS 3 PARTS (TB/TPS,CONTROL TAC, AND PEDAL TPS.)

6.0L told so the answer. is.
yes this engine is TBW , throttle by wire. see that TB see the huge motor on side of TB well it sticks closed, there is no IDLE air.
scan the PCM yet, see DTC errors, never skip scanning or go broke guessing, the tools is free RIO paid for 1st shop hour labor not paid.
see?
TBW errors, DTC , throttle by wire, errors must not be ignored
and goes to limp home mode or stalls.
or is low fuel pressure;. this too, is a tool for fuel rail pressure at spec, if low can be FPR stuck open or weak pump./
best is scan at the same time as the stall, (real savvy like that)

bad TB motor or bad throttle pedal assembly , the system as up to 4 TPS. (
2 up top, and 2 in the pedal, all cars with TBW , all TPS POT.;s
must agree, or car goes dead or is 20MPY limp home restricted.

so fast right foot fails to save the stall
but if the TB motor is jammed that foot is ignored.
TB = throttle body, all Xyz names here are ASE/SAE standard names./
oops 6.0L has IAC, my tech answer is the IAC is faster than that huge TWB TB motor . so IAC is clogged. lean IAC and TV, throttle valve.
are your cars foot pedals FIXED, (not adjustable option)
who GM has spare TPS sensor for throttle pedal assembly,
nice that, if DTC say any TPS bad it is.
this is the pedal TPS, , TWB TB sensors is there and changed by you, but pedal has one too. I scan first and not go broke throwing parts,
2001 Chevrolet Silverado 2500 HD .USA truck.
reading cars schematics NOW the pedal has 3 POTs. not 2.
APP 1 TO 3, ) AND TO POTS IN THE TB TPS UP TOP FOR 5 TOTAL POTS.
TBW ,MEANS GM TAC MODULES ALL. TB+TPS + APP)
Accelerator Pedal Position (APP) Sensor


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Code 78 APPS Main and Code 79 TPS Main are diagnostic trouble codes (DTCs) that can appear on a 1997 Mitsubishi Pajero. Code 78 APPS Main: This code indicates that the APPS (Air Pump System) Main relay is not working properly. The APPS relay is responsible for supplying power to the air pump, which is used to control the air-fuel mixture. Code 79 TPS Main: This code indicates that the TPS (Throttle Position Sensor) Main circuit is not working properly. The TPS sensor is responsible for sending information to the engine control unit (ECU) about the position of the throttle valve. If either of these codes appears, it is important to have the vehicle diagnosed by a qualified mechanic to determine the cause of the problem. The mechanic may need to test the APPS relay, the TPS sensor, or other components in the fuel system. Here are some possible causes of Code 78 APPS Main and Code 79 TPS Main: Faulty APPS relay: The APPS relay may be faulty and not be supplying power to the air pump properly. Faulty TPS sensor: The TPS sensor may be faulty and not be sending accurate information to the ECU about the position of the throttle valve. Clogged air filter: A clogged air filter can restrict airflow to the engine and cause the APPS relay to overheat and malfunction. Low fuel pressure: Low fuel pressure can cause the APPS relay to overheat and malfunction. Faulty wiring: The wiring to the APPS relay or TPS sensor may be damaged or corroded, causing the codes to appear. If you are experiencing problems with your 1997 Mitsubishi Pajero and either Code 78 APPS Main or Code 79 TPS Main appears, it is important to have the vehicle diagnosed by a qualified mechanic to determine the cause of the problem and to get it repaired as soon as possible.

Throttle Position Sensor (TPS) do go bad. Replacing it should not be difficult or expensive.

which one, some have 2, one is TPS other is MAF.
post a photo with finger pointing?
TPS: (guess 1)
that is the first step in the FSM book made.....
on all cars. "disconnect the battery before replacing electrical parts."

the only danger here, is losing radio codes, and NAV on new cars.
some cars need to do a relearn steps. (FSM covers all this get one)? (alldata.com or at toyota or used off ebay>)

on many cars the TPS, its called, needs to be calibrated.
why hot read the FSM and follow the simple steps.
no engine stated so I can NOT be specific.
you dont know whats under the hood and you are fixing it>?

94 camry. V30 model.
ill try my dice. I roll and land on.
6 camry, and 2 engines, and i guess USA>
https://parts.olathetoyota.com/toyotaoemparts.html
i guess DX and 2.2Liter.

1994 is big time transition year, so...... need all that.
up to 8 engines used world wide, but not in USA. we had 2.
one is a V6, got that?

ill post FSM qoutes to prove my case (not like changing a light bulb)
1MZ-FE

1. Loosen the sensor screws. Apply vacuum to the throttle opener, if equipped.
2. Insert a 0.021 inch (0.054mm) feeler gauge between the throttle stop screw and lever.
3. Connect an ohmmeter to terminals IDL and E2 of the sensor.
4. Gradually turn the sensor clockwise until the ohmmeter deflects and then tighten the screws.
5. Using a 0.014 inch (0.035mm) feeler gauge between the throttle stop and lever, verify with an ohmmeter that there is continuity.
6. Using a 0.030 inch (0.070mm) feeler gauge between the throttle stop screw and lever, verify with an ohmmeter that there is not continuity.

5S-FE? got that?

The TPS set wrong will cause the following problems.
1: Cruise failure.
2: EFI IDLE controls dead.
3: automatic transmission, shifting issues.
and more.


FIRST DISCOVER ENGINE TRUE NAME ,
then ask questions about it. like 1MZ-FE.
or??

alldata.com shows 6 engines.
and i can tell you they are not the same. not at all.
all diffr. EFI too.

I do not have Cummins codes so I would consider replacing the injectors or taking it to a Cummins service centre to have it fixed as the parts will not be cheap if not diagnosed correctly

The P2121 means Throttle/Pedal Position Sensor/Switch "D" Circuit Range/Performance.
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autel maxidas ds708

P2121 Code is throttle/pedal position sensor/switch D circuit range/performance
P2122 throttle/pedal position sensor/switch low circuit
Bad pedal maybe, does it return to idle?

To get the meanings of these codes go to
http://www.obdii.com/obdii.html
P2121 - Check with dealer on this code
P2127 - Accelerator Pedal Position (APP) Sensor 2 Circuit Low Voltage
P0483 - Cooling Fan Rationality Check Malfunction
P0243 - Turbocharger Wategate Solenoid 1
P0541 - Air Intake Heater Circuit Low
If you are located near a National Auto Parts store (AutoZone, Pep Boys, etc.) I would take the truck in and have them run diagnostics.
Let me know if you have any other questions. Thanks.

I think the terms "Throttle Positon Sensor", TPS and "Throttle Body" can be misleading at least in regards to the 04 Camry.

My 04 Camry gave a diagnostic reading of P2121 for my problem "Throttle PEDAL position switch D circuit". However, we changed out the complete Throttle Body/TPS (Toyota Part #22030-0H020) that did NOT fix problem.

The 04 Camry TPS Electronic Module "Throttle Positon Sensor" is factory assembled and riveted to the side of the throttle body. The only way to service/inspect it would be to cut off or drill out the rivets. Not sure you could open the darn thing if you got it off, but that seems to be the only way Toyota sells them!!

Hopefully a new Throttle PEDAL Position Sensor (Toyota Part # 78010-33010 PEDAL ASSY, ACC)
will fix it. This is located under the dash near the accelerator pedal.

So, now I would recommend FIRST to replace the "Throttle PEDAL Positon Sensor" (it is much, much cheaper) and then the Throttle Body/TPS assembly!! Unless of course, you get a diagnostic code as you did for "faulty throttle body!!