Hi all,
I have a 2004 Saab 93 2.0t Linear. It has just over 101k miles and so far it has been great. Just a few weeks back the car went into what I imagine is limp mode. Power was greatly reduced, but it was most noticeable at low speeds. I took it by a friend to have the code read and it showed up as P0601 which is an engine control module checksum error. So I did plenty of searching and found that replacing the module should fix the issue. A temporary solution was unplugging the battery which resulted in the car going back to normal for a bit.
I went and bought a used module from a local junk yard and sadly that didn't solve the problem. I took the used module to the dealer to have it programmed and immediately after driving I noticed a huge difference. The car seemed to lack power at certain speeds. The engine would idle very roughly when first turned on. I went back to the dealer immediately and they really weren't going to help since they didn't diagnose the problem. So I drove it for a bit, but it hasn't gotten better. I also noticed that gas mileage is much worse with this module. The SID would usually average 30mpg or more for highway driving, but now it is around 23mpg. A day or two later the check engine light comes back on and this time the code is P0300 which is for multiple/random misfires.
I looked into that code and found various issues that are related such as a vacuum hose that may be cracked or plugs or coils that need to be replaced. I looked at the hose where it commonly cracks near the dipstick and mine seems to be fine. I also looked at the spark plugs and they don't look bad. I haven't driven with the used module for many days because I feel as if it is doing more harm than good. I put the original module back in and the car drives fine for several days before going into limp mode again or dieing while driving.
I am currently looking for any advice available. With the original module the car drives just as I would expect it to. With the used one it drives much worse with reduced power. It seems that the P0601 code is very rare to get and most people that reported the issue didn't respond after they had it fixed. Also it seems many of them had it covered under emissions warranty which my car is not eligible for since that warranty is only 80k miles. Sorry for the long post, but I really have researched this quite a bit and it seems like the only option is to take it to the dealer and buy a new module if that is the solution. I really would appreciate any help. Thanks.
I have a 2004 Saab 93 2.0t Linear. It has just over 101k miles and so far it has been great. Just a few weeks back the car went into what I imagine is limp mode. Power was greatly reduced, but it was most noticeable at low speeds. I took it by a friend to have the code read and it showed up as P0601 which is an engine control module checksum error. So I did plenty of searching and found that replacing the module should fix the issue. A temporary solution was unplugging the battery which resulted in the car going back to normal for a bit.
I went and bought a used module from a local junk yard and sadly that didn't solve the problem. I took the used module to the dealer to have it programmed and immediately after driving I noticed a huge difference. The car seemed to lack power at certain speeds. The engine would idle very roughly when first turned on. I went back to the dealer immediately and they really weren't going to help since they didn't diagnose the problem. So I drove it for a bit, but it hasn't gotten better. I also noticed that gas mileage is much worse with this module. The SID would usually average 30mpg or more for highway driving, but now it is around 23mpg. A day or two later the check engine light comes back on and this time the code is P0300 which is for multiple/random misfires.
I looked into that code and found various issues that are related such as a vacuum hose that may be cracked or plugs or coils that need to be replaced. I looked at the hose where it commonly cracks near the dipstick and mine seems to be fine. I also looked at the spark plugs and they don't look bad. I haven't driven with the used module for many days because I feel as if it is doing more harm than good. I put the original module back in and the car drives fine for several days before going into limp mode again or dieing while driving.
I am currently looking for any advice available. With the original module the car drives just as I would expect it to. With the used one it drives much worse with reduced power. It seems that the P0601 code is very rare to get and most people that reported the issue didn't respond after they had it fixed. Also it seems many of them had it covered under emissions warranty which my car is not eligible for since that warranty is only 80k miles. Sorry for the long post, but I really have researched this quite a bit and it seems like the only option is to take it to the dealer and buy a new module if that is the solution. I really would appreciate any help. Thanks.