Dealership says it's my ECU but..

Hello there, I'm a bit new to this but always come on here for research. Recently my car is unable to pass smog. I do not have a check engine light on.

A little back story on my car:

I had a whole bunch of lights on about a year ago took it to a speacialized European shop in my town to see why it was doing all that. Guy told me it was the abs control module. I replaced it and most of the lights went off except for the abs light and traction control light. Recently had to go get my car smogged figured it should be a breeze since nothing's wrong with the car. Obviously not the case based on the title of this thread- anyways, guy said my o2 sensors and cat monitors are not ready, he said to drive it, I drove it for 300 miles all sorts of ways, fast, slow, cruising, driving 55mph and then coasting down to 25mph. Went back to the smog guy, same thing so I took it into vw dealership in town they said it's cuz my o2 sensors are bad so I replace it (at home thank you very much) drove the car for 150 miles like I did before. Take it back to get smogged. Still. Not. Ready. Take it back to vw. Some odd tests and 3 days later they saif they were able to make the traction control light and abs turn off because the other vw that coded it didn't run the final "test" thing and that's why the light didn't turn off, they also then tell me my ecu is bad. I have no check engine light, as far as I know from reading on other sites I have no systems of a bad ecu.

I dont trust the dealership with a lot of things just because of past experiences. If I need to give more information on the vehicle please let me know!

ANY IDEAS ARE APPRECIATED.

Depending on if your car is tuned or not you may never pass smog. Some tunes dont check the o2 sensors if younare catless so it will never come up ready.

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I've owned my car for three years it's all stock cuz I'm making payments on it. But their are no upgrades to anything except for parts that needed replacing.

I would check readiness in vag-com, you may be able to force them as well to get it passed.

I dunno about forcing readiness on things that dont test

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I don't own a vag com otherwise I would've already done that. I just don't know what to do about this. No symptoms of a bad computer other than what the dealership says.

Smog tests sound so horrible. lol

They ar D:

*are

Could a tune up cause my sensors to not be ready?

zepholose said:

they were able to make the traction control light and abs turn off because the other vw that coded it didn't run the final "test" thing and that's why the light didn't turn off

Click to expand...

LOL....I ran into this issue when I tried to have a friend recode my car through vag-com so the ESP-off button would turn it OFF rather than just reduce its effects. It just gave my car those lights and was wanting to perform that final "test" you described. I was thinking about that when I was reading the first part of your post. I ended up just driving it with the lights on for quite a while and they finally just turned off on their own. Hope you get your other issues figured out....does not sound like bad ECU symptoms to me.

Carista

Carista app also works very well at diagnostic, telling if emissions ready and resetting codes. Easy to use and not a lot of money.

Yeah I drove with those lights on for a few months lol that wasn't really the main thing though. It's still not ready to be smogged (checked with my OBD2) I can't reset the sensors or anything like that but I'm really not sure what else to do. I ordered a refurbished ecu to do a swap see if it works if it doesn't then I gotta take it back to vw :/

Readiness script if you want to try it.

Readiness Code, Setting
Diagnostics are performed at regular intervals during normal vehicle operation. After
repairing an emissions related system, a readiness code is generated by road testing the
vehicle.
If a malfunction is recognized during the drive cycle, it will be stored in the DTC memory.
The OBD drive cycle operation will be monitored with a hand held diagnostic tool. Consult
the manufacturers instruction manual for correct tool operation.
The readiness code is erased every time the DTC memory is erased or any time the battery
is disconnected. If the DTC memory has been erased or the battery is disconnected, a new
readiness code must be generated.
Only erase the DTC memory if a DTC has been stored.
General Recommendations
Most monitors will complete easier and quicker using a steady-foot and smooth acceleration
during the drive cycle operation, cruise, and acceleration modes.
Operating Conditions
For the EVAP monitor test, the coolant temperature and the ambient air temperature must
be between 10 degree C and 35 degree C with a difference between them no greater than 4
degree C. The ambient air temperature must not change more than 4 degree C during the
drive cycle procedure (e.g. when driving out of a heated workshop in the winter).
Test requirements
Erase the DTC memory Diagnostic Mode 04 - Erase DTC Memory .
Coolant temperature must be between 80 degree C - 110 degree C.
The Intake Air Temperature (IAT) must be between 10 degree C - 35 degree C.
Battery voltage must be a minimum of 12.5 volts.
Fuel tank level 1/4 - 3/4 full.


CAUTION!
When performing the drive cycle operation, pay strict attention to
driving conditions and please observe and obey all posted speed
limits. Failure to follow these instructions may result in personal
injury or possible death.
Drive Cycle Procedure
Connect the scan tool.
Switch the ignition on and start the vehicle.
Idle the vehicle for 2-3 minutes. This executes the O2S Heater, Misfire, Secondary AIR,
Fuel Trim, and Purge system monitors.
Drive the vehicle at 45-55 mph for a continuous 7 minute period, avoid stopping. This
executes the EVAP, O2S, Fuel Trim, and Misfire monitors.
Accelerate the vehicle to an engine speed of 5000 RPM (with automatic transmission use
the tip-tronic mode) lift off the throttle until the engine speed is around 1200 rpm. This
executes the fuel cut off
Accelerate the vehicle smoothly to 60-65 mph, cruise constantly for 5 min, this executes the
Catalyst; O2S, Misfire, Fuel Trim, and Purge System monitors.
Decelerate and idle the vehicle again for 3 minutes. This executes the Misfire, Secondary
AIR, Fuel Trim, and Purge system monitors.
Check the status of the readiness code.
Note:
Depending on the scan tool used. The readiness code status may be displayed as
complete, passed or OK.
If any engine monitor fails the drive cycle test. Repeat the drive cycle test until all engine
monitors have successfully run through and passed.
Note:
When repeating the drive cycle operation for a failed EVAP monitor or thermostatmonitor,
allow the engine to cool until the coolant temperature and the ambient air
temperature are be between 10 degree C - 35 degree C with a difference between them
no greater than 4 degree C is observed and repeat the drive cycle operation.
If the drive cycle operation fails again.


Check the DTC memory for stored DTCs Diagnostic Mode 03 - Read DTC Memory .
Repair the vehicle if necessary.
Repeat the drive cycle operation until all engine monitors have successfully run through
and passed.
Remove the scan tool and switch the ignition off.
End of procedure.

Sooo a little update. I found an ECM that was refurbished for a pretty low cost. Had it replaced and coded or whatever. Everything checked out fine got it to pass smog (yay!) now I have a check engine light code is P0507 Idle air control system RPM higher than expected. It didn't have that before I changed the computer... could it be a coincidence or could it be that something somewhere got messed up in the installation process?