I farted around with this problem off and on for a couple more weeks and tried to figure out what the problem was to no avail. Everything appeared to indicate a PCM
problem. It was so intermittent, I wasn't sure of anything.
Took it to the FORD dealer early this morning and told them to fix it... The service manager made sure to tell me it could cost up to $170 just for the diagnostics. Then there would be the parts and labor to make the repairs.
The shop manager called me after lunch to tell me what was going on. Here is a summary of what he said:
"It's a recently discovered problem on the newer Taurus. There appears to be an intermittent low voltage condition at the PCM
that causes all the symptoms you described. The FORD engineers are aware of the situation and are working on a solution. At this time, they don't have any kind of fix for it and it could be July or August before they have one. Don't quote me on this, but FORD will probably issue a recall for this. We reflashed your PCM
and cleared the codes. Your car is ready to pick up anytime you are ready. There will be no charge for the service."
It seems to be running good now, but it did that off and on before I took it in. I hate the thought of waiting until July or August for a possible fix. I asked about replacing the PCM
and the shop manager said "it would just do the same thing." You can be sure that I'll be taking it back in, when or if starts doing it again.
The intermittent symptoms were weird...
Multiple OBDII codes, P0351 thru P0356
Engine running rough, SES light off
Engine running rough, SES light on
Engine running good, SES light on or goes out after a few miles
compressor turns off and on (PCM
Doors unlock and lock while driving
Anti-Lock Brake error displayed when coming to a stop (Stalling?)
Stalling in traffic (did this once)
Average MPG keeps resetting to zero
Complete loss of electrical power, no lights, no door locks, no anything and some kind of relay clicking continuously under the dash (did this twice while parked, but cleared up after switching ignition on/off a few times)