How to test throttle actuator on 2006 2007 2008 Mazdaspeed3 with P2119 fault code

[Lex2007]

RELATED VEHICLES: 2007-2012 CX-7, Mazdaspeed3, Mazdaspeed6 2.3L Turbo L3 w/TC

SUMMARY: P2119-Throttle actuator control throttle body range/performance problem; The PCM compares the TP with the default TP value when the ignition switch is turned off. If the TP position is higher than the default TP value, the PCM determines there is throttle actuator control throttle body range/performance issue, a DTC is set and the MIL is illuminated. One trip detection. Symptoms may include: Lack of throttle response, vehicle in limp mode.


TSB 0102410; Some vehicles may experience MIL illumination with DTC P2119 stored in memory when the engine is started, then it shifts into "Limp Home" mode and the engine output decreases. This may be caused by worn throttle valve internal drive gears causing friction to increase. The throttle valve may not properly return to the fully closed position when the ignition is shut off.

PROBABLE CAUSES:

Throttle Body
Powertrain Control Module (PCM)
Wiring or Connectors

RELATED COMMUNITY CASES:

Lack of power, do not accelerate
P2119, Intermittent No Throttle Response

DIAGNOSIS:

HINT: Check to see if the above referenced TSB has been done before continuing with troubleshooting.

1. Disconnect the throttle actuator (at the throttle body) connector and check resistance of the throttle actuator motor as shown in diagram below.



If results are NOT as expected, replace the throttle body assembly.
If results are as expected, check for opens or shorts between the throttle actuator connector and the PCM.

Here is another version of the same instructions:


THROTTLE ACTUATOR INSPECTION

Resistance Inspection
1. Remove the battery cover.
2. Disconnect the negative battery cable.
3. Disconnect the throttle body connector.



4. Measure the resistance between the throttle actuator terminals using a tester.
- If not as specified, replace the throttle body.
- If as specified, carry out the "Circuit Open/Short Inspection".

Circuit Open/Short Inspection
1. Disconnect the PCM connector.






2. Inspect the following wiring harnesses for an open or short circuit (continuity check).

Open circuit
- If there is no continuity, there is an open circuit. Repair or replace the wiring harness.
- Throttle actuator terminal F and PCM terminal 2A
- Throttle actuator terminal E and PCM terminal 2B

Short circuit
- If there is continuity, there is a short circuit. Repair or replace the wiring harness.
- Throttle actuator terminal F and power supply
- Throttle actuator terminal F and ground
- Throttle actuator terminal E and power supply
- Throttle actuator terminal E and ground

If you need a new throttle body assembly, the OEM part # L3Y1-13-640A is and the gasket ispart # L3K913655

According to one supposed Mazda mechanic: https://www.justanswer.com/mazda/65n...ting-wall.html

1. Check with Mazda (1-800-222-5500) if the throttle body was replaced under TSB 10-024/10. Description:
Some vehicles may experience MIL illumination with DTC P2119 stored in memory when the engine is started, then it shifts into "Limp Home" mode and the engine output decreases.
P2119: Throttle actuator control throttle body range/performance problem.
This may be caused by worn throttle valve internal drive gears causing friction to increase. The throttle valve may not properly return to the fully closed position when the ignition is shut off.
As a mass-production change, additional grease has been applied to the throttle valve internal drive gears.

[Lex2007]

I took some pics while testing the wiring harness. (I'm no expert so feel free to chime in advice). Testing the actual throttle actuator while its installed on the car is super hard due to access with the probes and being able to isolate pins on the actuator to test for resistance (ohms). I couldn't do it. You CAN easily do it with the throttle body out of the car but A. you're gonna need a new gasket to reinstall it afterwards and B. Your gonna need to pinch the coolant lines into the throttle body so you don't spill coolant. So first, lets test the wiring harness.

Testing the harness from the plug into the actuator and to the plug into the engine computer is easy. This is the OPEN CIRCUIT test listed above. The pictures in instructions above are a little confusing so here are some pics of which pins to back-probe with the your multimeter in CONTINUITY MODE. You need the needle type back-probe ends. The regular probes that come with a multimeter will not work. They are too thick and too short.

Just unplug both the plug into the actuator and the plug (the one closer to the front of the car) into the computer.

I started with checking for an OPEN CIRCUIT in the harness. With the multimeter in continuity mode, preferable with an audible alarm for when you have continuity, put either probe all the way into pin F of the actuator plug shown in my pic:



And the other probe all the way into the back of the corner pin 2A of the plug that goes into the computer as shown in the pic:



Its the red/green wire. Very top corner wire. Push the back-probe until it bottoms out and makes contact with metal.



If you have continuity then that wire is transmitting to the PCM.

Then go to the next connector in the throttle actuator plug, pin E, like so (sorry about the washed out picture):



and then move the back probe in the computer plug into the pin 2B just below as so:



Again you should hear a tone from your multimeter showing continuity.

If youre not getting continuity then the wire to and from the plugs is damaged somewhere along its length or inside the plug.

Now test for a SHORT CIRCUIT in the same harness. In other words a wire is bare and touching the car's metal somewhere along the way between the 2 plugs :

This time, as per the instructions, with your multimeter in CONTINUITY mode, you push either back-probe into PIN F (or E) of the throttle actuator and touch the other back probe to 1. the positive of the car battery and 2. The ground of the car. Neither should show any continuity. If they do its because you have a bare wire touching metal in the harness between the 2 plugs.

An easily accesible ground is next to the battery. Now is a good time to remove it, clean it with some mechanics sandpaper or scotch pad or whatever and reinstall it.



and



And then use the same pin in the throttle actuator plug and touch the positive car battery terminal (my battery was out, but you can leave yours in)



Now move the back probe to the other pin in the throttle actuator plug and touch the other probe to the positive battery terminal and then to ground.

You should NOT get continuity in either case. If you do, one of the wires is exposed in the harness and touching metal. You need to find and wrap it in tape and protect it from happening again.

ONE LAST THING:


Check the pins on the engine computer. Pins 2A and 2B, are they blue? They could be oxidized as could the metal connection inside the plug. My PCM terminals and the terminals inside the PCM plug have had a lot of corrosion in the past. I think its the gases from the car battery causing the corrosion.

I actually had to open up the plug and replace a terminal some years ago(I started a thread on the subject with pics). It was causing a CEL and stumbling. The stealership claimed I needed an entire wiring harness...bastards wanted like $3000. I changed one pin inside one of the the PCM plugs and soldered the wire ends.

I also use DEOXIT D100L (Amazon or Ebay, not available in box stores) with the little paint brush (looks like a nail polish brush) on the pins and let some drip into the tiny holes in the plug to clean and protect. Or CRC 05101 QD electronic connector cleaner spray for the plug itself if you dont have a corrosion issue but just wanna clean and protect (Autozone, Advance, PepBoys etc). I like the paint brush because application is very precise. I would use this even if your pins look good.



Deoxit D5 spray is also good for the pins inside the plug since they cannot be easily reached. The D100L is thicker though so I like it more.



After a 3rd limp mode episode, I ended up changing the throttle body assembly with a Spectra Premium TB1025 unit from Amazon for $360. All seemed fine until I test drove the car. It went into limp mode with CEL and traction control light (a first) within 3 blocks. I checked the plug into the assembly and it seemed to be connected even though the red tab would not lock into place. Maybe she lost connection...not sure.

I limped home, checked the codes:

P0123 Throttle / Pedal Position Sensor / Switch A Circuit High Input
P0222 Throttle / Pedal Position Sensor / Switch B Circuit Low Input
P2100 Throttle Actuator Control Motor Circuit /Open

I turned car off and back on and cleared the codes and put a ziptie under the connector and tied it into place so the connector cannot back out. She seems to be running normally. Not sure if this is a connectivity issue or PCM. Will let you know if she goes into limp mode again with the SPECTRA unit.