P0351 Code on my Jeep Grand Cherokee?

Question

I have a 96 Jeep grand Cherokee... 4.0L 4x2 w/ the same problem w/ 202,000 miles. and it's been recently that i've been working through this problem for Ignition Coil #1. So far i've changed the Throttle Position Sensor, fuel pump, fuel filter, both Oxygen sensors, the engine wire harness, the PCM, and ignition coil, camshaft position sensor, crankshaft sensor, the rotor, distributor cap, ignition wires and spark plugs. I have totally run out of ideas. I have some of the diagnostic manuals for the GC and tried following the wiring schematics. There is a [B]grey/white[/B] wire that goes from the coil to the PCM, a [B]dark green/orange[/B] wire that goes from the PCM to the ASD relay, according to the schematics, these wires are linked to the Primary Coil#1 code. i could see how that could work out w/ just placing a wire directly from the Coil to the PCM, but i've replaced the engine wire harness so i cant imagine how i could have the same problem, pls help!!!

Answer 1

Wow, you've changed a lot of stuff. The coil should have power at all times and a switching signal on the ground. When the ground turns off the coil feild collapses, triggering the spark.



I think its a loose pin on the ecu connector, seen it a few times on chryslers.

Answer 2

You have done a commendable job in restoring the powertrain control system.

I just checked the ASE site for anything related, and found nothing.

The only thing I could contribute are two---

1) Seriously look at ALL of the grounds.Do a voltage drop test on all of them. The system may be trying to feed a circuit backwards if it can't find its dedicated connection.

2) Try a little retro diagnostics. Even though this vehicle is OBD II compliant, and the protocol is in place and active, the OLD diagnostics are still in most of the Chrysler products as well.

Try cycling the key on, off,on, off, and then on within 5 seconds and watch the MIL. It should still flash out codes, and if it does, refer to the same make, model and engine for a 1995 for diagnostic procedures.

For a clearer discussion of the procedure and description of the codes, Go Here----->



http://autorepair.about.com/library/ts/obd-i/bl-dtcs-75a.htm.



And as you are now no doubt aware, diagnose the circuit or system and NOT just the component.



Good Luck

Answer 3

i will say that the laptop is inflicting the subject because of the fact I even have the jeep restoration OEM handbook and the code PO351 does not exist in this 365 days nor the 5.2 liters or the 4.0 L engines i will recommend that attempt with a accepted solid laptop you will get it much less costly in eBay.

Answer 4

check your catalytic converter

Answer 5

does it run ok? let it be or let dealer work on it.