96 Grand Caravan Blowing Ignition Coils

I have a 96 Dodge Grand Caravan 3.3L V6 w/ 140K miles. Engine
suddenly began running rough, check engine light came on, and vehicle
stalled after another minute or so. Mechanic replaced Cam Sensor and
Ignition Coil. Vehicle started up and ran fine for about five miles
and then same thing happened. Based on code 351, Ignition Coil again
replaced and vehicle again started and ran fine for about five miles
before happening a third time. Code again shows 351. What is causing
this?

 

I'd bet crank sensor. It's not bad practice to replace both cam and
crank sensor as a set. You see what happens is over time the fine
wiring in the sensors cracks. Then when they heat up, the wires are
spread apart and the sensor stops working. When one of them goes the
other is close to going too.

A decent mechanic would have used a scope on all of the engine sensors
and the ignition coil, when
the engine was hot, before replacing any of them. Sounds like your mechanic
is a "parts changer" I'll bet your first coil had nothing wrong with it.

Ted

 

Your "mechanic" is an idiot.

P0351 doesn't mean the coil is no good. It means the PCM has detected
a problem in the #1 coil circuit. It "could" be caused by a bad coil,
but there are other possibilities such as wiring problems or even the
PCM. Find somebody competent and have it checked properly.

A crank sensor will not cause this.

 

The ignition coil is supplied 12 volts by the ASD relay to ignition coil
primary circuit 1-2 and 3.The PCM controls all 3 primary circuits by
grounding each circuit. The problem could have been a bad coil, but it
sounds as if the first pot shot was already thrown at it and didn't fix it.
The second shot taking was so far off it is silly. The crank sensor will not
effect this circuit. You need to find another person to work on this vehicle
or go by your self a DVO meter and fix it your self. Since the vehicle is
running we know that there is 12v coming from the ASD circuit feeding the
primary 2 and 3 side therefore we need to look for a bad wire/terminal from
the coil gray wire at the coil connector to the PCM connector pin #11. if
this wire is not open circuit from point A to point B then we know the PCM
is bad and needs to be replaced. If you had a scan tool you could activate
the Primary 1 circuit and the PCM would make and break the ground. such an
easy test to make and diagnose. If the problem was intermittent it may be
hard to diagnose. Since your vehicle is a hard fault and running bad at the
time of the test it should have been diagnosed in 15 min.

Glenn Beasley
Chrysler Tech