Solving CEL P2138, U1102 and U0122
 

Hi guys,

I cleared my CEL P2138 but it just keeps coming back every 6 mths. The earlier time I had this CEL, I replaced my entire pedal position sensor with a new unit , tightened up the slack on the throttle cable and cleared the code. The P2138 code went away but 6 mths down the line, its back again :( I borrowed a scanner to clear it and its gone now but am mystified why it keeps coming back?

The other 2 codes I get, namely U1102 and U0122, have never gone away. They seem to be there in the background, cannot seem to be cleared by the scanner but don't seem to adversely impact my car's performance.

U1102 Loss of Serial Communications for Class 2 Devices
U0122 VSA-PCM

I have no idea what a class 2 device is and owning a Dec 07 AP2 means I dont even have VSA. How can something I dont even have throw me an error code?

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Utah S2K, on 08 September 2011 - 06:04 PM, said:

........
The Ucodes are up the food chain and harder to reset for a reason.
U is network connection failure
--0 is an SAE code (society of automotive engineers)
--1 is a manufacturer code
----1 is air and fuel control
--------02/22 are specific codes which track to specific (exact problem code)
--------These codes track directly to OBD I codes
My guess basedon the info is that when the Hondata gasket was installed you have an air leak or TPS damage/ midwife.
Clearing adaptive memory codes can be difficult but Canberra accomplished by disconnecting the battery for an extended period of time ( I use 2 hours).

My advice would be to have someone find out why you threw the first two codes, correct that, and the U codes will clear themselves.

Utah

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I had no Hondata gasket installed. My TPS sensor (attached to my throttle) is a totally brand new unit which I bought in error thinking it would solve my P2138 code so there should be no problems with it.

Seeking some help here from the tech gurus!

How can you not have VSA? The DBW system is part of the VSA system.

:iagree: all 2006 and newer S2000s have it. I saw the mention of tighening the Throtle cable though :confused:

Hi Billman,

I really dont have VSA. No switch nothing. mine is a jdm 07 AP2.

Johns2000,

The cable runs from the accel pedal to the APP sensor unit.

Some kind of swap? Perhaps the ECU is looking for the DBW setup, whilst there is only the conventional cable setup. So since there is no electronic sensor at the pedal, only at the Throttle Body, the ECU is not seeing the Pedal sensor?

Man...I dont get it :)

The purpose of the DBW throttle is to allow the VSA system to control the throttle electronically.

I'll believe you and ask this...all JDM s2ks have no VSA switch?

Can you drift the car?

Yup there is a cable from the gas pedal to the controller under the hood on North American cars also. This cable is adjustable should you want to adjust it or remove freeplay. You must take the cover off the controller to do so. From the controller to the throttle plate, its electronic.

Billman: other JDM ap2's I see are mostly 08's and they have vsa with the switch. Yes i can drift my car, just turn the steering, rev high and pop clutch and I can get donuts at will. On the track my tail will come out should I turn in aggressively, so it's clear to me that vsa isn't present.

According to your codes, your car posses the protocol for VSA.

is it possible the system was removed by someone?

Can you use a flashlight and look at the dash, see if the Triangle light is there? /_\ with ! in the middle.

Hi Billman, car has only had one owner from day one which would be me so nothing has been removed. Only "electrical" work done was a flashpro.

Checked my dash and there isn't any triangle light. Only thing I can think of the possibility that my car was manufactured in 06 but sold to me in 07!