First of all, I’ve added this to my previous CEL problem back in Dec '19 and Jan '20
Original ECM being replaced by a used one but both have the exact same Audi part number and manufacturer’s number. My Audi is a 2008 A4 3.2L Quattro Avant with Tiptonic auto transmission.
Original has had a P2404 (EVAP problem) for some 4 years that the dealer has declared the ECM is at fault and needs replacing. All tests including wiring and vacuum lines are ok.
They want $2,439 + $80 to set it!
In addition they said the vacuum was 19.1 inches at the leak detection pump and should be above 20 so they want to replaced the booster vacuum pump for $858!. I bought a new one from a supplier in Phoenix, AZ for $48.56 + a gasket locally and replaced it myself. Not easy but worked out fine with vacuum now at 20.5
I bought the used one from a parts salvage yard in Lithwania, $123.xx including shipping, which was delivered via DHL in three days two hours! (pretty amazing!) I replaced the original with the used one without disconnecting the battery (bad me but…) then turned on the ignition without starting. SAFE appeared where normally the total mileage would. The trip odometer remained at 157.X. OBD II meter had 6 codes: 4 for the cam, 1 for fuel pump, and the dreaded P2404! The VIN number was different but checking on it showed the ECM came from a 2008 Audi sedan with a 3.2L engine.
Question: should I clear the codes and start the engine? Anyone’s suggestion here would be greatly appreciated.
I’ve posted here before about fuses I could not find for the ECM but after removing the improperly secured case for it, discovered the fuses and the TOTALLY corroded and rusted relay switches that causes some 9 code errors just a few months ago. Both replaced and I’ll put that episode in this forum sometime latter with photos.