1998 VW Jetta P0605 ECM Failed
The check engine light is on my 1998 VW GTI Jetta. Autozone scanner gives troubleshooting code P0605 Failed ECM. What is the ECM and where is it located?
Calvin from Baton Rouge, LA
Hi Calvin. The OBD-II generic description for a P0605 DTC code is Internal Control Module Read Only Memory (ROM) Error. Basically what that's telling you is there is a fault in the internal memory of the ECM (engine control module). So replacing the ECM does at first sound like good advice.
On your '98 Jetta GTI the ECM is located in the middle of the car under the windshield. If you remove the wipers, you can then remove the cowl cover over the ECM, and drain area for rain water. I'm sorry I don't have a diagram handy, be sure to get your hands on a quality service manual for your VW Jetta repairs.
With that said, there is a good chance that you might not actually need to replace the ECM. I came across a great thread at TDIClub that shows a plastic tube on the ECM that sometimes leaks and/or fails which can result in this P0605 engine code. So before you run out to buy another ECM, get yours out, and look for that tube, I would suggest you try replacing that tube first before replacing the ECM. The ECM will have to come out of the car anyway to replace that tube. Here's a photo from that thread showing the tube: