I realize that there is tons of info on this subject. I want to see if anyone has experienced this. I just finished washing the car, 93 348. Did a pretty thorough job on the louvered engine cover, i.e. lots of water on engine. After drying the car off, I went to go for a short cruise. After warming the car up for about 5 minutes, I got in in to back out of the driveway. SLOW DOWN 1-4 light came on steady, not flashing. Car has no power and is idling very rough. Could this be due to water from washing? If not, I see where many of you have sugggested disconnecting the battery for 20 minutes in order to reset the ECU's. Can I simply use the battery disconnect switch under the hood above the front left tire, or do the battery cables actually need to be removed entirely from the battery? Thanks
Probably those pesky exhaust ECU's if that's the problem, it will not go away when the engine drys out. Most people just disconnect them, but you'll have no warning of cat overheating if you do.
I washed the 348 the other day and covered the engine REAL GOOD with trash bags. I've seen these threads b4 and didn't want to take a chance..
If you lost a bank there may be something going on other that just a pesky ecu. Try it tomorrow after it has dried a little more and report.
Last evening, (about 8 hours after the problem surfaced), the car started and ran fine. I had disconnected the battery for that length of time, and when I restarted the car, I let it idle without touching the gas for about 15 minutes, as prescribed in many posts. I went for a 30 minute drive, got everything good and warm, and drove with the revs fairly high at times. Everything seemed to be OK. Not sure what happened. I will definitely post any further developments, I know cars don't typically heal themselves.
It's not the Italians' fault. The electronics and connectors are either German (Bosch), Japanese (NipponDenso), or American (Delco), depending on the year model.
I think a plug connector is getin wet and the plug isn`t firing. The fuel will injekted to the cylinder with no firing and goes to the catalysator and heat it ,up so the warning light goes on ,and shut down the whole bank After you washing the car ,blow out humidy and water with light airpressur from the ignition system , you won´t have these problems again, and the car must not heal itself by drying out in he garage.
One of your ECU's is likely letting moisture inside via a small crack. Once wet, the affected sensor will malfunction & turn on. Once dried out, the sensor will function properly again & light will stay off. Regards, Rob.
What will cause a slow down light to come on at 3500 rpm and go off at 3800 rpm. If you are to slow down, why does going faster do the same thing?