SC has developed an electrical drain & other issues
10-12-11, 08:48 PM
#1
SC has developed an electrical drain & other issues
It's a 98 SC300.
A few days ago when starting it the starter was much louder and not nearly as smooth starting. It got worse day after day. Then it barely started.
Once it started it was running fine until today.
I started and put it in drive and the car barely moves forward. I had to rev to 1800-2000 rpm to get a 2 mph speed that is just normal at cold idle taking your foot off of the brake.
I took another car to work and found the battery drained to 9.8 volts at the terminals when I got home.
The battery is about 2 years old and does not appear to have issues. A charger has been hooked up and I will see if it hold a charge; if not I will just remove it and have it tested under load at the place I bought it.
The transmission issue is what scares me. With the engine running the alternator is putting out enough juice so the headlights are at full brightness. I do not know if the transmission issue is related to the low voltage in the system due to the battery being unable to hold a charge; the ECM for the transmission may not be getting a proper signal to go into drive. I do not know.
Car ran fine with no issues prior to this. Now the transmission slipped so badly it feels like this was a chronic problem that was neglected for years
BTW: no warning lights at all if I can get it started
A few days ago when starting it the starter was much louder and not nearly as smooth starting. It got worse day after day. Then it barely started.
Once it started it was running fine until today.
I started and put it in drive and the car barely moves forward. I had to rev to 1800-2000 rpm to get a 2 mph speed that is just normal at cold idle taking your foot off of the brake.
I took another car to work and found the battery drained to 9.8 volts at the terminals when I got home.
The battery is about 2 years old and does not appear to have issues. A charger has been hooked up and I will see if it hold a charge; if not I will just remove it and have it tested under load at the place I bought it.
The transmission issue is what scares me. With the engine running the alternator is putting out enough juice so the headlights are at full brightness. I do not know if the transmission issue is related to the low voltage in the system due to the battery being unable to hold a charge; the ECM for the transmission may not be getting a proper signal to go into drive. I do not know.
Car ran fine with no issues prior to this. Now the transmission slipped so badly it feels like this was a chronic problem that was neglected for years
BTW: no warning lights at all if I can get it started
Last edited by texan_176; 10-12-11 at 09:08 PM.
10-13-11, 05:39 PM
#4
It turned out to be the battery at fault. It would not hold a proper charge no matter what. I removed it from the car and took it to the store for them to charge and test it. It failed the testing. New battery in, car cranks up like normal, and pop into drive and it's ready to go.
Low battery voltage seems to have some kind of impact on the transmission ECM.
I am very surprised that no warning lights came on at all.
Low battery voltage seems to have some kind of impact on the transmission ECM.
I am very surprised that no warning lights came on at all.
Thread
Thread Starter
Forum
Replies
Last Post
