Hello! I'm getting the yellow engine light and my acceleration has been stunted tremendously. 2013 justa

My code reader is giving me the following codes:
P2138 - Throttle/pedal position sensor/switch 'D'/'E' voltage correlation
A8BD - FRM: Number-plate light faulty
2B4B - Accelerator pedal module, pedal position sensor, signal 1
2B4E - Accelerator pedal module, pedal position sensor
2FD9 - EWS -DME interface
5E30 - DSC control unit, voltage fault, undervoltage
5E31 - DSC control unit, voltage fault, undervoltage

I replaced the accelerator pedal module and a relay (61.36-8 373700/01) and I'm still having the same problem. I plan to replace the throttle position sensor next. Any advice would be appreciated. Thanks!

 

If you clear the codes, which ones persist?

 

@Maybe, maybe not I will try this out tonight and get back with the answer. Thanks!

 

@Maybe, maybe not
These are the codes tcode came right back after clearing:
A8BD - FRM: Number-plate light faulty2B4B - Accelerator pedal module, pedal position sensor, signal 12B4E - Accelerator pedal module, pedal position sensor

 

Does your scan tool support live data?

Do you have a multimeter, and do you know how to use it?

Based on your answers, you may need this ....

 

This is what I have and I'll admit my knowledge is limited on both. I'll take some youtube academy classes if need be though

 

Your first step is to check the power and ground circuits at the APP.

Disconnect the electrical connector from the APP sensor, switch the ignition on to the accessory position, and verify you have 5 VDC on pins 3 & 5. Do not stick the meter leads into the harness connector since this will spread the terminal apart and damage the connector.

Next, check both APP ground circuits are good. Connect the black meter lead to a known good ground and the red meter lead to pin 1 then pin 2. You should see less than 300 mV.

 

Alright, I got 5 VDC on 3 and 5. Then i got 3.8 mV on 1 and 2.

 

Power and ground circuits check good.

Next step will be to connect your foxwell tool and pull up the APP signals You should see a correlation between Voltage from APP1 and APP2. If they don't, and that's the fault you have by the way, either your new APP module is defective or your DME is.

 

Great! Power and ground circuits are fine. You either have a faulty APP module (I've seen a lot of failures of aftermarket parts right out of the box lately), or the problem is in the DME. Your best bet is to pull a known good APP module out of another R56, and see if that solves your problem. If it doesn't, suspect the DME.

Use your Foxwell and pull up the live data in the DME; go to foot pedal. Select APP1 and APP2. The two should correlate. Voltages will be different, but the voltages should rise and fall like they do on my car. See pics below. At full throttle I see 4.55 volts on APP1 and 2.25 volts on APP2.



With the throttle released, I see .72 volts on APP1 and .36 volts on APP2.

 

I did my best with my Foxwell tool. The closest live test I could get was labeled "percentage, pedal position". It gave me a "0" reading when I gave it gas. Interestingly, it gave an 89.84% reading when I put the clutch to the floor...

 

The clutch? Why are you pushing the clutch pedal down when you're troubleshooting an accelerator pedal (APP1_APP2) fault? DId you do this test with the engine running? The engine doesn't have to be running.

With the throttle fully depressed your pedal percentage should be 100%

 

I tried with and without the engine running and got nothing from the accelerator. I pressed the clutch out of shear curiosity.

 

My '09 Justa is an automatic. Weird that the clutch has to be depressed to get the APP signal to register. Still, you should see 100% when fully depressed.