For answers to your Acura Vigor question go to
The answer is found on (read answer below)
Sometimes, the ECU will give an erroneous Code 4.It gets tricked! A bad alternator may put out voltage spikes which make the ECU think the Crankshaft Position Sensor is bad. Sometimes it will put the engine in "Limp Home Mode," which limits the engine to 3000rpm and causes it to hesitate.
Sometimes, a Code 23 or Code 53 (Knock Sensors) will be indicated instead.
To test the alternator, drive the car with all accessories off and the CEL should not come on. When you turn on all the electrical stuff (lights, blower, defogger), the alternator should be able to keep up with the demand. If turning on the accessories sets the CEL and you get the same code, your alternator is bad.
Another way to test it is to remove the round connector from the back of the alternator. If the symptoms go away"”and then return when you plug it back in"”the alternator is bad.
Give thanks to a Vigor user all the way in ARUBA :)
Sunday, August 24th, 2008 AT 5:18 AM