Greetings,

My 02 MSC started off with a bad day - I tried starting her up this morning and it turned over with a really rough idle, I had to step on the gas to keep it from dying. I tried restarting it 3 times to no avail - same problem. Alas I ended up driving my 2nd car to work.

One of two things recently happened to my car -
1 . Off and on for the past week, my car has been hesitant to start - almost like the battery was starting to go (still the original factory battery)

2. Saturday - My Friend ran my car while parked running A/C full blast in this crazy California weather for an extend period of time - Any folks from AZ or TX ever have a problem with running A/C idle in hot weather for a period of time? No problems with starting or driving after this for at least a day or two.

Then Monday - problem as described as above.

Of these two - could it be a battery need replacing - I was planning on this as part of preventive maintanance. How would this account for the engine starting - but extremely rough idle????

Or two - Did using A/C under hot weather fry something???

TopGearNut

 

Most likely the battery - other postings have said that the original battery doesn't go much past three years.

 

Update - Battery Replaced with a new factory unit

Problem still exists - It has a really rough idle and when I rev the motor it still only goes up to about 4000 rpms w/pedal floored. It's almost like it starts in what I've read as being in limp mode. SENS light, Check Engine, ASC light comes on...

I'm stumped - I'm having a friend check it out today - he thinks it might be the plugs or electrical now. Last straw is taking it in to the dealer - I just know I'm gonna get killed on the repair costs

 

Could these problems have been triggered by a faulty bypass valve?

 

I was just look at another thread about that - I'm wondering how I can go about checking if the bypass valve is bad? Any ideas?

Thank you

TopGearNut

 

Update:

Car finally started properly the next day after letting it sit overnight with the new battery. The DSC, EML lights didn't light up again yet the Service Engine light stayed on. My friend came over and pulled the spark plugs which were black (I'm swapping those out tonite with new ones) and ran an ODB II check on the car - came back with P1229 and P1125. Any ideas what these codes might be???

I'm gonna swap out the ignition cables too.
Air Filter is getting cleaned as well as the TB was taken out and cleaned also.
After all items were put back - we reset the codes and let it idle for a while with no codes coming back - I'm gonna run the car tonite to see if it comes back.


TopGearNut

 

The Bentley manual says P1125 is Throttle Position Sensor A and B Range/Performance small error. P1229 Throttle Sensor Adaptation failure.

 

thanks for the code translation - hopefully they won't come back after the part change.

Thanks again

TopGearNut