ECM failure

I took my '07 Taurus to Auto Zone the other day to get my check engine light checked. We received an "ECM failure" message, which is kind of puzzling to me. The battery and alternator both tested fine. As for the car's performance, I don't know if it's all related, but......

From time to time when I drive it for a while, get out and go into a store, when I come back it won't crank right away, but after a few seconds it cranks right up. Then, when I drive it and park and take the key out while getting out, I hear a fast "clicking" noise, and at least one of my meter gague sticks on the dash wags back and forth. Sometimes, when I go to unlock the doors with the keyless remote, the dome light, mirror lights, and a couple other just flash for about 20-30 seconds.

Also, in idle it runs with a hesitation, but doesn't turn off.

Any ideas on whether any of this is related, and/or what could be causing it? I'm not planning on tackling it myself. I just want to get as much information as I can before I take it to a mechanic.

Some of the symptoms you describe sound like they could be due to a low voltage condition. How old is the battery in the car? With it being a 2007 if it's on the original battery, regardless of how it tests, it's probably not good. In that case I'd suggest you start by buying a new battery, cleaning the cable connections, and installing the cables on to the new battery securely.

When you turn the key to the Run position, do all the warning lamps in the instrument cluster illuminate for the bulb test? Now what happens when you turn the key to the Start position and hold it there?

-Rod

Thanks for responding Rod. If I remember correctly, this battery is about 2 years (maybe a little more) old. When I first switch the ignition on, all the lights (Fuel, check engine, seat belt, air bag, brakes, battery, oil, and theft) come on, and when I start it, the fuel seat belt, and brakes lights come on. The fuel and brakes lights go off.

I think I've heard somewhere that this model of Taurus goes through batteries within a couple years. Is that true?

The charging systems in many late model vehicles are quite sensitive, your Taurus could be one of them. I've also learned that time flies, so what feels/seems like 2 years may be more like 5 years. Not to mention that if you replaced the battery 2 or 3 years ago, you only got 2 or 3 years out of the original battery so it could very easily be due to be replaced again.

If you have a multimeter and a friend you could test the charging system to see if it is likely the cause of the poor start and hesitation. After taking the car for a drive, when you think it may not want to restart, put the meter on the battery posts and try to start it. If you get the car to where it just clicks, read the voltage on the battery when this happens. Then move the meter leads to the battery terminals and see what the voltage is. If there is a considerable difference between the two readings, then you either have a bad cable, loose connection, or a dirty connection.

For those times when you get the rapid clicking, what does it finally take to get the car started? Do you need to jump start it or do you just need to wait a few minutes and try again? If you just need to wait, does the starter seem labored in turning the engine over?

-Rod

Thanks Rod.
No, I don't have a multimeter, so I wouldn't be able to check the charging system. The guy at AutoZone checked it, but he didn't check the difference in the battery posts and the battery. Of course, it hasn't actually done any of this in almost two weeks, so I can't reproduce the issue. I'm still willing to just go ahead and change the battery once I get a break from the rain.