InMyRearView

I have done evrything to try and fix my "reduced engine power" problem that i keep having. It has been throwing codes P2176 and P2135 (which i have done my research on) and i have replaced my gas pedal and my throttle body and it seems like it is only a bandaid for the problem. Is there ANY other hope? Are there any Corvette Specialists up in the Albany area or upstate region close to Albany that can diagnose this problem? I spoke with someone today and they said that since it happens intermittenly (driving or parked) its possible the key is not programmed correctly and the car may think it is getting stolen so it shuts itself down. but i dont know if that would throw the aforementioned codes. ANY HELP IS GREATLY APPRECIATED!!!

nj02vette

What mods do you have?

First thing I would do is take it to a reputable tuner. Most reduced engine power problems that I know of come from a problem of actual airfow exceding expected airfow. It goes into reduced power mode to prevent runaway acceleration.

(Toyota, are you listening).

It's a common problem when tuning on C5/C6 where the airflow gets messed up because of an unplugged MAF.

I looked up what I could find and didn't get any info on the P2176 and P2135 codes. Don't have them on my list.

But simple things like upgraded MAF can really eff up the tables in a tune.

I don't know enough about the C6 control systems to suggest any other hardware failures. Maybe a dealer visit is in order.

InMyRearView

thanks for your input. i have an Airraid intake, Borla Exhaust, and an UD Pulley.

2135 code is TPS 1-2
2176 code is TPS not learned

or vice versa but i kno they have to do with the TPS.

6spdC6

Give Howard a call. he has done some work for me in the past and he knows a lot about C6 Vettes.



-518-355-8460

howard@redline-motorsports.net


Dave a previous long time Albany-Colonie resident, now living about 60 miles away!

LMB-C6

The manual call's out using a scan tool for some diagnostic steps, a generic scan tool may not have access to what you need to monitor. IIRC, the generic ones just give TPS position, but there are some other things you can check. Also, if you are not skilled in doing diagnostics like this, take it to someone who is....we don't want to cause more damage than what's already there.

That said, here's a little info based on the DTC you posted.

P2135: TP sensor 1-2 correlation. The difference between TP sensor 1&2 exceeds a predetermined value for more than 2 sec.

Looks like it will set if there is high resistance in any of these signal lines: Sensor 1 (or 2) signal, sensor 1 (or 2) 5-volt signal, sensor 1 (or 2) low reference. Anything else seems to set a different DTC. For instance, shorts to ground or opens set different codes.

Testing:
Ignition off. Wait 2 minutes for everything to power down.
1) Test for less than 5 ohms between low ref circuit (terminal C) and ground.
2) Ignition on, test for 4.8v-5.2v between 5v reference circuit (terminal E) and ground.
3) Verify scan tool TP sensor 1 voltage less than 0.1v.
4) Verify scan tool TP sensor 2 voltage greater than 4.8v.
5) Install a 3A fused jumper wire between terminal D and terminal E. Verify TP sensor 1 voltage now greater than 4.8v.
6) Install a 3A fused jumper wire between terminal F and terminal C. Verify TP sensor 2 voltage now less than 0.1v.
7) Ignition off, disconnect ECM harness. Test for less than 5 ohms between ECM terminal 65 to TP terminal D; ECM terminal 63 to TP terminal F; ECM terminal 3 to TP terminal 3.
8) Test for infinite resistance between TP terminal D and terminal F.

From the diagnostics, if everything checks out, they say to replace the throttle body, which you said you did. Some steps indicate a possible bad ECU. My $ would be on some condition causing resistance (corrosion, etc) on one of the wires.

Let me know how you make out.