Mechanics

ELECTRICAL

1996 Plymouth Voyager • 6 cylinder 2WD Automatic • 130,000 miles

P1391. I've replaced crank and cam sensors with oem. Checked all wiring I can trace. Changed ignition switch. Ignition module. Still setting p1391 code. Please help
Avatar
JEFFJ
August 25, 2011.




Which engine do you have?

The first thing to do is find a mechanic with a Chrysler DRB3 scanner. It will display "No" or "Present" for both signals while on a test drive. That will let you see which signal is dropping out.

Did your new crank sensor come with a thick paper spacer on the end? That is needed to set the critical air gap. If the gap is too large, the signal will be lost intermittently.

Besides the sensors, there could be a corroded splice between the two ground wires or between the two 8 volt feed wires. Also look for stretched terminal pins in the connectors.

Caradiodoc
Aug 25, 2011.
I HAVE THE 3.3 V-6.I AM READING 9.6 VOLTS AT EACH SENSOR ( CAM AND CRANK). IS THAT ACCEPTABLE VOLTAGE? I'VE ALWAYS DEALT WITH A 5VDC SYSTEM. IS CHRYSLER TRULY AN 8VDC SYSTEM? YES NEW SENSOR HAD CARDBOARD FOR AIR GAP. I AM PRETTY CONFIDENT IT IS SET PROPERLY.
AD

Tiny
JEFFJ
Aug 31, 2011.
These are 8 volt sensors. 9.6 volts is higher than I've ever seen but shouldn't cause a problem. Check the voltage on the ground wires too. It should be very close to 0.2 volts. If it's high, there's excessive resistance somewhere between the sensor and the Engine Computer.

The best way to see what the computer is seeing is to use the scanner to view sensor data. That way you can wiggle wires and irritate connectors to see what causes the code to set.

Caradiodoc
Aug 31, 2011.

AD