My 2003 Camry 4-cyl engine had the check engine light go on for a few days. The light has since turned off on its own. I took the car to AutoZone to get the codes read. They said it was P2238, but their online system did not have an entry about what that code meant. The code is still being reported by the car's computer even with the check engine light off. Is this a serious problem when the check engine light is off?

Welcome to the AF!

There is a TSB for '03 camry for code P2238

Vehicle is probably a 4cyl (PZEV) CALIFORNIA EMMISIONS vehicle.
It needs a ECU Update, that is normally done at a dealership. I have heard there is a flash program available for non-dealer maintenance.

If the calibration has already been done then I have heard it will need A/F Ratio sensor #1 located in the top of the Exhaust manifold. Bring your VIN to the dealer to get the correct part number if you have to change the sensor.

TSB:
Make : TOYOTA
Model : CAMRY
Year : 2003
Manufacturer : TOYOTA MOTOR NORTH AMERICA, INC.
Service Bulletin Num : 01503
Date of Bulletin: OCT 28, 2003
NHTSA Item Number: 10004499
Component: ENGINE AND ENGINE COOLING:ENGINE

Summary:
http://www-odi.nhtsa.dot.gov/images/spacer.gif MALFUNCTION INDICATOR LAMP (MIL) ON WITH DIAGNOSTIC TROUBLE CODE (DTC) P0031, P0051, P2238 OR P2241. *TT

According to this it's something effecting barometric pressure sensing. Just put P2238 in the blank. At least the dealership will have a clue with the TSB.

http://www.iequus.com/support/obd2_definitions.php

I've scheduled an appointment with the dealership to get this looked at. I spoke to the service advisor on the phone telling him the fault code and the related TSB, but he said they would still have to charge me an $80 diagnostic fee. I will let you know what they find out.

In case you have the wrong impression, a TSB or technical service bulleting is only a notice to Toyota mechanics that a trend has been detected and they are directing this or that action to correct it. The customer pays for whatever maintenance is completed for a given TSB unless it falls under a normal or special warranty. It's just a tool to help the mechanic.

P2238 Generic
O2 Sensor Positive Current Control Circuit Low Bank 1 Sensor 1

P2238 Mazda
Oxygen Sensor Pumping Current
Circuit Low - Bank 1

P2238 Toyota
Barometric Pressure Circuit
Intermittent

Interesting, so that's where the A/F Ratio sensor diagnosis came from. I didn't realize that the codes could vary so much between generic and manufacturer-specific.

:p I just picked up my Camry from the dealership service department. The fault code P2238 was still in the car's computer, but the check engine light was off. The service rep showed me the TSB that matches the one described earlier in this thread. They had to flash program the computer with new firmware. Fortunately for me, the TSB carried a 96-month, 80000-mile warranty for this repair so I did not have to pay anything to get it fixed. I had done a little more research on this particular TSB at ***Links deleted by Moderator*** and found that all sources agreed on what the problem was.

you can't beat toyota customer service...at least i don't think so. even with TSB's, if its a common problem it seems they tend to extend the warranties on the specific problem. such a thing happened to me and saved me $450. I'm happy to hear that worked out for you.

Brian, I had assumed that generic and manufacturer specific codes varied quite a bit to begin with. Your comment makes me think that this isn't always the case and that more often then not, they will agree. Has that been your experience with them?