GFallen

Posted in the tuning section with no answers so i'll try here... My airflow tables are being maxed out in the TB, my tuner guy raised them 5% but car still goes into reduced power mode...Does anyone know what % they should be raised to? Car is ls2 and maggied thanks...

DMM

5% is not nearly enough with FI, here are my before and after tables as an example...

Stock Tune: 0.90 1.40 2.71 3.21 3.70 4.18 4.65 5.11 5.55 5.99 6.41
Maggie Tune: 6.35 7.54 8.73 10.32 11.90 13.89 16.27 18.65 21.83 25.00 28.18

Since this is just a (calculated) condition to set a DTC, its ok to open them up a bit. As an FYI - this is not an adjustment that needs to be made in the VE tables, this adjustment needs to be made in the tables found under "DTC'" --->"Airflow"--->"Maximum Airflow Delta - P0101"

Hope this helps!

itsslow98

iTrader: (18)

Sounds like you need to take the car to a reputable tuner.

vmapper

iTrader: (8)

DMM is correct.
There is also the maximum MAP vs TSP %... cant recall the P0 # at this moment.

and "Your tuner guy" - doesn't sound like a "Tuner", but one practicing to be one, so I would have to agree with itsslow98 as well.

GFallen

He actually is a real good ford guy..has the record for fastest cobra frank at Psi motorsports..just not real familiar with ls motors...the car ran great at first. Thanks for input Dmm

vmapper

iTrader: (8)

That may be,. but that doesnt change the fact to know the tables and how the GM ECM works. (E40 for example, or E38) - for the different ECMs/PCms/TCMs.

Right off the top of my head, the ford means of measuring air for fueling is completely different than GMs

Here is an example.

for the MAF sensor:

GM sends a signal frequency wave (GM) (varying square wave), which then interprets the frequency to the corresponding tables to get grams/cyl for fueling

Ford uses a voltage 0-5Volt (DC) to the ECM which then interprets the voltage for determining grams/cyl for fueling.

GFallen

I have an appointment next week but after doing some searching im wondering if my accelerator pedal sensor is bad, on another post someone had same code and symptoms I had. Does anyone know the part number?

vmapper

iTrader: (8)

I would personally just focus on correcting the DTC values before jumping to assumptions of accelerator pedal sensors.
Reduced power mode ... we dont know the CEL codes given...
you are running FI....
with the limited info provided...My money is still on the Airflow Delta tables...

GFallen

Code p2135..i said its a ls2 maggied

RADEoN

iTrader: (12)

GFallen, did you happen to use a throttle body converter harness?

DMM

Alright man...P2135 is "Throttle/Pedal Position sensor switch A/B voltage correlation.

What this refers to is that there is a voltage going to the throttle body to open it, and a different voltage coming back as being reported as the "Throttle Position". There are 4 of these in the LS2 software (A/B is code P2135 and D/E is P2138).

What is happening here is that a specific voltage is applied to circuit "A" to open the throttle, and a separate voltage is also on circuit "B". For the sake of an example, let's say that ckt "A" is from 0 volts (closed throttle) to 5 volts (WOT), and ckt "B" measures from 5 volts (closed throttle) to 0 volts (WOT). These are separate voltages to negate the chance of a short applying voltage to the second circuit.

The voltages on both circuits must correlate with each other...using the above example, if ckt "A" was reading 1 volt, the PCM would expect to see ckt "B" with 4 volts. Again, these are not going to be the actual voltages, just for the sake of an explanation. Your specific problem is that the voltages on "A" and "B" do not correlate in a linear fashion as expected within the tables, and the PCM cannot positively determine the throttle position, so it locks it in "Reduced Power Mode" to prevent over powering the brakes and causing a possible runaway situation .

The PPS (Pedal Position switch, gas pedal), throttle body, PCM, or wiring can all cause this. The most likely cause of a voltage correlation code is additional resistance introduced into the circuit, usually at a connector. Since your throttle body harness was extended, it may be better to re-solder both ends of the extension connections, at least for the A/B circuits and see if that helps. It could be the PPS also, since it is basically multiple rheostat switches combined into one.

With the PPS (Gas Pedal), you have to make sure that you get the exact one for the PCM and throttle body that you have. Mixing and matching pedals, throttle body's, and PCM's can brick the PCM, or cause weird *** problems like having 100% throttle at 30% throttle input. This is b/c the A/B and D/E voltages are all unique to the pedal, PCM, and throttle body.

Hope you understand this and it helped. If nothing else, you can give me a call now that I am back in town.

vmapper

iTrader: (8)

We all get that its maggied (F.I.)
The code is probably the most important information lacking in troubleshooting until now.
No need to comment as DMM has explained it.