This is my first time posting and I'm hoping you experts out there can give me some advice. A few months ago, my check engine light came on for my 2003 Camry with the codes P0038 and P0058, so I had my O2 sensors replaced. A few days later, the light came back on with the same codes. Mechanic tested all of the sensors and they all tested fine. Couldn't figure out why the light kept coming on. I even replaced gas cap and fuel filler neck but that didn't do the trick. Car runs beautifully (always has) so just kept driving. Now it's time to get smogged and can't because of the light. Took it to Toyota dealer and they confirmed O2 sensors and heater control circuits are fine. They told me I needed a new Engine Control Module (ECM). Spent $1,200 on that (which I thought was too high) and I won't even know if that will do the trick until they install it and I drive a while. I wouldn't think the car would drive well if the ECM was bad. All I want to do is get my car smogged and getting very frustrated!!! Like I said, the Camry drives beautifully!!! Any thoughts you all could provide would be much appreciated.

 

maybe wiring glitch or too much voltage sent to the 02 sensor heater wires from ECM/PCM
HO2S Heater Control Circuit High (Bank 2 Sensor 2)

Read more at: https://www.obd-codes.com/p0058
Copyright OBD-Codes.com

https://www.obd-codes.com/p0058

If the PCM detects an abnormally high voltage condition on the heater circuit, P0058 may set. This code is only referring to the heating circuitry half of the Oxygen sensor. Bank 2 is the side of the engine that does not contain cylinder #1.


P0038=HO2S Heater Control Circuit High
P0038 - OBD II Trouble Code


A power-train control module, abbreviated PCM, is an automotive component, a control unit, used on motor vehicles. It is generally a combined control unit, consisting of the engine control unit (ECU) and the transmission control unit (TCU).

 

Thanks Dirty Hands! The test that the Toyota Dealer performed said "Tested for voltage between terminals HT1B, HT2B and E1 of ECM connector. Showed 12.4 Volts. Test result is a failed ECM". Once they replace the ECM (this weekend), do you think there's a good chance the light stays off or could there be other problems based on the high voltage? I understand this question may be "unanswerable" but thought I'd try

Thanks again!

 

you already replaced and tested both new 02 sensors and they pass

when the codes point to 02 heaters and voltage reading is too high only gives you one option

replace ECM

when all done ..should be no reason to fail smog

 

Thanks again for your insight, Dirty Hands... I really appreciate it!!!

 

Suggest you wait as long as possible to have the car tested.

The new computer will need to run through all the self tests and until then the testing will be incomplete. State smog specifications only allow so many tests to be incomplete before they fail the car.

This doesn't mean the car has an emissions issues. It just means the computer has not finished running all its tests. The tests can require several driving trips each meeting certain conditions such as MPH, duration, etc.

 

Thanks, Toyomoho. Do you know how long I have to drive the car? Every time the check engine light goes off I drive it for a little bit and then take it to the smog shop, but they put something into the car and say that it's not ready to test because the codes have not cleared out yet. Does this make sense?

 

Yes, this makes sense.

The smog shop is plugging into the cars computer. The machine they use is stating the car (computer) is not ready for emissions testing.

The computer self checks various components and systems related to smog. It then stores the data as what passed and what did not. It also stores how many of the checks have been performed.

When the computer was replaced all this data was reset. The result being all checks need to be run again.

Most states allow a limited of number of tests not to be completed and still be able to run the smog test.

There are specific driving patterns the computer tracks when doing a test for a specific code but I don't have them. As such its not a function of drive time in minutes or hours but type of driving done, hence the name Drive Cycle.

Suggest an internet search on "Toyota drive cycle readiness for emissions" or such to find hits like the one below:

Toyota Drive Cycle Readiness Monitors for Emissions smog check

The process may require a few repeats from the engine being cold started.

 

Thanks Toyomoho... this is very helpful!

I appreciate all of the information!!!