I just redid the voltage and resistance readings as well as a visible inspection of the wiring.

The voltages were as indicated before 5 volt, but I was misreading the meter on resistance. In addition I had the pins wrong on the bad side


So on the bad side Vref 300 Ohm
monitor 5.3 KOhm
pin 1-3 4.6 KOhm

good side 22 KOhm pins 1 and 3
4.6 KOhm 1to3

 

I will post a link to a google site with pictures

 

I also just tried the voltage readings at the bad sensor with the engine running and no change

https://goo.gl/photos/UDRL5F6p8aHokfqC9

 

I am hoping the wiring checks out tomorrow. Would/could a bad PCM give funny resistance readings? How often do PCM's fail. They are basicly solid state right?


To double check do you know what pins I need to check on the PCM relative to the FPS pins 1,2, and 3

 

When you say zapped .....is zapped permanent or could a reflash be performed. Could this be from storm damage or lighting?


Do PCM's wear or would a used one be as good as new one?

 

How are you measuring resistance? Are you measuring from the pin on the sensor plug to the pin on the PCM plug? With the PCM unplugged? 22Kohms for a piece of wire is a lot. I would expect minimal resistance from the sensor plug to the PCM plug. I would expect infinite (not connected) between pins 1 & 3 with the PCM unplugged. With the PCM unplugged, if you see something other than infinite between any of the pins then there's a short somewhere.

Rereading through the thread there are two possibilities: 1) the sensor wire for bank B is somehow shorted or 2) The PCM is somehow internally shorted. Those are the only way I could see the PCM reading pressure without the sensor being connected. I'd try to somehow pop the pins out of the PCM plug for the sensor and see if it still reads 75 psi. If it does then you know the fault is within the PCM.

 

I have not removed the wheel yet to measure the wire resistance at the PCM...I am measuring the resistance on the wire connected to the PCM.

I figure if there is no resistance on the wire when I disconnect it from the PCM then it has to be the PCM.


I will try to remove this connection from the pcm...perhaps I can insulate the connection

 

Well now it gets fun....Went to start the car for diagnostics and it fired right up.

 

The engine is running on all 12 now....I backed out of the driveway and it died. Same pulled back in and restarted. Drove around the block died. Restarted drove a couple miles died..restarted. Now I cant get her to fail. Checked resistance and got same readings as before. Fuel pressure readings fine. 45 lbs

I got code 606 on both sides when she died and a 1798 can bus error.

PCM's have intermittent errors? Battery issues? Ghosts?

 

Test Drive

 

I am not sure .....now I have an intermittent problem. I have an appointment at the Aston Martin dealer in February. I think I might trailer the vehicle to Nashville to get the car scanned and the PCM's flashed.

The battery is an Interstate and is 2.5 years old but I have not had the car but for 7 month don't know what this battery went through and AM's are hard on battery. I may just replace it with a gel cell or high capacity battery

 

I dont think it is the wiring now. Because every time it would die I got a 606 code and it would always clear on a restart. If the problem wire was shorting the trouble would not go away on a restart.

If you have an electronic device that has a fault I would think it would be a good possibility it would clear itself upon restart.


Make sense?

 

Back to her old tricks again.....Damn

 

Couple of observations. Started this morning no problem. Cut the car off. Started not problem. Backed the car out put the car in drive went 15 feet Problem arises again.

Park the car. Now the car wont "reset". Come back an hour later starts and drives. I drive 2 miles problem again. Park the car now the car will restart

The car has never "reset" while driving....only upon restart. When the car also goes into fault it is like someone flipping a switch

 

other than voltage what do i do to check the battery?