My jeep threw a couple of codes, need help figuring it out
 

My jeep grand cherokee was driving down the road and all the sudden an occasional miss started, like 1 miss every 5 minutes. I stopped went in to run an errand and came out, started it, put it in reverse and it died. almost didnt want to start back up. Barely made it home chugging and trying to die. I get home and its idling perfect. A friend of mine says his did the same thing and it was a crank position sensor. I figured what the hell, put one in, and did a tuneup(plugs,wires,cap,rotor). Initial start ran fine, then died, did the exact same thing.

Got a code reader, and heres what i have

1. PO351 Ignition Coil A Primary/Secondary circuit malfunction

2. PO740 TCC Circuit Malfunction

What should i do from here?

1996 Jeep Grand Cherokee, 4.0 inline 6, automatic.

Thanks

Re: My jeep threw a couple of codes, need help figuring it out
 

Chry products have had alot of problems with their ignition
coils. Replace the ignition coil, most likely its
failing. They can act up intermittently. The tcc code is a
trans torque converter code. Could be caused by a bad torque
converter solenoid. You have to test for power at the solenoid.
should have power with key on. Computer commands the ground
to the solenoid. Just a simple trick to see if torq is engaging.
drive down th road in o/d at about 45-50mph. lightly tap the brake
pedal with to accelerator holding steady at speed. If the tack jumps
up about 200 rpm,you know the torque is engaging. It could be
a old code if the trans ever got low on fluid. You cant check key
cycles with a code reader. If you need to get more technical, let
me know.

Re: My jeep threw a couple of codes, need help figuring it out
 

Try the pickup coil in the distributor.

Re: My jeep threw a couple of codes, need help figuring it out
 

So which one should I replace, ignition coil or pickup coil?

Re: My jeep threw a couple of codes, need help figuring it out
 

I had gotten a similar coil code on my 96. It came when I was towing my boat up hill, but I didn't have the misfire. It turned out to be a bad oxygen sensor at the cat. You can also check codes by cycling the ignition key on and off 5 times, leaving it on the fifth time (without the engine running). The check engine light will flash the codes, and the odometer will display them as well. A 55 means end of codes.

Re: My jeep threw a couple of codes, need help figuring it out
 

Pick up coils are no longer used.The were on older
vehicles before they went to cam & crank sensors.
Code 351 will only set when pcm detects peak coil
currant was not reached in 2.5 milliseconds of dwell
for 3-6 seconds.It will also only set when asd relay
is energized. The ecm will only trigger the asd relay
if it has a proper crank signal & sync. coil primary
resistence is .95-1.20 ohms. secondary is 11.300
to 15.300 ohms. 99 % its the coil,could be wiring
from coil to ecm,but not likley.

Re: My jeep threw a couple of codes, need help figuring it out
 

damn, sure sounds like you know what your talking about
:D Ill pick up a coil and put it in tommorrow. My friend said his crank sensor did the same thing to him. I replaced that, then checked the codes :(

Re: My jeep threw a couple of codes, need help figuring it out
 

reset the ecm and retest,once a problem is sent to the ecm it is stored there,sometimes it wont affect drivability depending on the code!with all those codes set it is possible they were intermittent!with the retest,this will narrow down your actual problem!emc stored codes will cause the parameters of the engine to change!the emc(computer)will retard the timming and richen up the fuel system so untill it is reset!this limp mode enables you to safley get off the road and to a tech for repair!if continuious driving is done in this condition aka(with the check engine light on),you can do some more damage than the original problem,burn out cat,burn out o2 senson,clogg erg ports in the manifold ect!leaving the gas cap off for three starts can even set your emc into limp mode!i would reset the ecm,drive car until light comes back on and then with your tester youll find your problem and eliminate the intermittent codes which probably happened while driving under limp mode with check engine light on!if i had to through parts at it though with out dianosing it,i would go with the crank angle senson or cam sensor,which ever one onyour vehicle is used to tell the ecm when to fire each plug!good luck!

Re: My jeep threw a couple of codes, need help figuring it out
 

Crank sensor failer is common on these Jeeps but so is a dirty throttle body that will cause it to die at idle or idle very poorly. Check the throttle body if its dirty clean it out and reset the idle through your scanner or disconnect your battery to relearn the pcm.

Re: My jeep threw a couple of codes, need help figuring it out
 

Guys,did you read his first post? He already put a crank sensor
in it! Same problem. His symptoms are consistent with a bad coil & the coresponding code.
By the way,if the crank sensor or cam sensors go bad,the
ecm will detect it being out of sync and ALWAYS set a sync
code. Thottle body crud will cuse stalling,but not off idle. He
said he was driving when it started to skip. definetly not a
throttle body issue.

Re: My jeep threw a couple of codes, need help figuring it out
 

Saw That,had To Re Read It,it Was A Little Hidden But Saw That!sorry,dont Put Another Crank Sensor,rest Ecm First!

Re: My jeep threw a couple of codes, need help figuring it out
 

Put a coil in last night. Started, hasnt thrown a code. When I first started, it hesititated a couple of times, but since then no problems. I sprayed out the throttle body (which was dirty) and put some of that BG 44k in the gas tank. So far, so good, no codes and im driving it today.

Thanks for all your help-

Jason

Re: My jeep threw a couple of codes, need help figuring it out
 

Ok, heres another one. Running great, i stop to get the mail, turn it off, go to restart it, wont start. wont spin over at all, and doesnt make any clicking noises. The volt meter doesnt drop when i turn the key, but the radio does stop while i am in the cranking position.

Heres what ive done so far.

1. check the battery with a load tester. tested fine, 12.4 volts, good under a load.

2. i turned the ignition on, and started the car straight from the solenoid on the battery, turns over and fires up as normal.

3. found the starter relay. switched it out with another relay with the same part number (for the a/c) nada.

4. tried starting it in neutral (in case it was the park switch)

nothing is working. i also opened the hatch with the key, in case the alarm wasnt disabling.

nothing is working. where would you go from here??

Re: My jeep threw a couple of codes, need help figuring it out
 

Take a test light & see if you get a crank signal from the
ignition switch to the relay. The neutral switch completes
the ground to set the relay.If you do get a crank signal,its
most likley a neutral switch problem. Not much to the system,
power to relay from ignition crank. Ground from neutral switch.
I have seen quite a few ignition switches go bad on Chry products. Its Fri night,I'll pull the schematics Mon. and
give you more specific info. (color of wiring).

Re: My jeep threw a couple of codes, need help figuring it out
 

:D I told you the coil was bad:D

Re: My jeep threw a couple of codes, need help figuring it out
 

My wifes GC had a simular problem over the summer. I could not find the problem. A mech friend could'nt either. Towed to dealer ($$$) & replaced the cam sensor & claimed they repaired wiring to the dist. Its a '93 inline 6.

For what its worth, the coil only had breif power at the coil when ign key was turned on. Even tried to run a hot leed to the + side of coil with no results. If your problem is the same, here's what the dealer had on the invoice;

"no cam signal at pcm/traced short in sensor/replaced cam sensor & repaired connector"

pn#53009077 sstator -d8029098 $88.00

Let me know if this helps, Stan

Re: My jeep threw a couple of codes, need help figuring it out
 

ok, heres some more info. I went out, just going to give it a try, and it started.

I drove it around, everything ok. Killed it, started back up. Then I thought i was checking the neutral safety switch, put it in neutral, no start. I jumped it at the starter and it started, but wouldnt start again from the key.

waited a day. same thing, started ok, then it wouldnt.

what should i replace. If I knew it was either the nss or the ignition, i would replace both.

One wierd thing, when i went to jump start it at the starter, it sparked, but didnt crank. took a couple of times to get the starter to turn over. maybe i was just hitting the wrong connection.

where should i go from here?

Im not going to let this jeep beat me! :D

Re: My jeep threw a couple of codes, need help figuring it out
 

Sounds like the neutral safty switch to me. You can take them off and clean them but you have to adjust them after reinstalling or the transmixer will shift funny.