0122 code a mystery.

[ryno56]

Also posted on CF for exposure.So my truck started acting up the other day... Driving at around 80kph I started to feel a light surging, it got progressively worse and then threw a CEL and I had significant dead pedal issues. I limped it home and checked codes. At that time it gave me p0122 and p0500. I cleared them and went for another drive. Same issues, but all it had was the p0122 code this time. I did an apps recalibration and the problem persists. Sometimes the code shows up in both the ecm and pcm sometimes just the ecm. The 0500 code has not returned. So I put on a used apps from a truck that was wrecked but running fine before... same issues, same code. I ran through the diagnostics procedure and could not find any wiring issues. After all the testing I now have an abs and brake warning light. I figure that may just be from having the key on with the computers disconnected. I tested the voltage output on the apps and it appears to be operating normally. Also, the TPS% display on my pulse monitor shows it operating fine when the key is on with the engine off but not while the engine is running. I haven't tested the voltage directly at the apps with it running but why would it change? The issue is the same whether the quad is connected or not.I don't have a DVOM good enough to test AC noise from the alternator but I did run the truck with the alternator disconnected and the problem was still the same.I have ordered a Timbo apps (just to rule out the used one) but I don't expect that to make much of a difference. I do have low fuel pressure issues but the truck has not been run above stock levels (except for timing) and I don't have any vp related codes. The vp does have a "remanufactured" sticker on top but I don't know how old it is. The truck has 194000 kms, I haven't driven it much since I bought it on Jan. 6th except for the 11hour drive home and a few trips to work. I have been stockpiling parts to do my mods once the weather warms up.Any ideas? Could it be the ECM? (Please say no)Ps. Definition for p0122 code is TPS low voltage.

[98whitelightnin]

When I got that code mine was the apps and a new one from Tim fixed my issues.

[ryno56]

When I got that code mine was the apps and a new one from Tim fixed my issues.

That's what I'm hoping for. I just don't understand how an apps from another truck would show the exact same issues.

[Mopar1973Man]

Best I can say is run the diagnostics... http://articles.mopar1973man.com/2nd-generation-24v-dodge-cummins/59-obdii-error-codes/151-p0122-apps-sensor-signal-voltage-too-low

[Homestead]

My 0122 code scenario started out with the APPS and slowly included all the sensors with voltage high and voltage low codes, ended up being the ECM.I'm hoping the new Timbo wipes your problem out, it didn't on mine.Like mentioned, run a thorough diagnostic check and go from there.Jeff

[ryno56]

Yeah I've already been through all that. I'm going to try a used ecm as soon as I can find someone to sell me one.