Jeep Garage  - Jeep Forum

Jeep Garage - Jeep Forum (http://www.jeepgarage.org/forums.php)
-   Troubleshooting/Problems (http://www.jeepgarage.org/f181/)
-   -   Need some troubleshooting help with P2305 (http://www.jeepgarage.org/f181/need-some-troubleshooting-help-with-p2305-34579.html)

99formulam6 01-23-2012 04:32 PM

Need some troubleshooting help with P2305
 
Ok, so this weekend, I decided to replace the EGR and put in new plugs (Champion 570's) in my 07 Hemi.

EGR went fine (unless you count having to take off alternator to remove it. PITA!)

Now, for the plugs...I started on the driver side and removed the connectors on the coils, then loosened the 2 bolts on each coil. I started on the rear most coil and when I tried to remove it, the rubber boot tore off the coil pack. I couldn't run and get a new boot, so I put everything back together so I could run to the store in the morning and get the new boots. I tightened the coils back and reconnected them. Naturally when I started the Jeep, it ran kinda rough and had a miss since that rubber boot was torn.

Sunday morning I run to Autozone and get two new boots for the rear coil. I replace them and start the Jeep and the CEL is still on and it is running rough. I have the Diablo with me, so I check the codes and see P2305 which is "ignition coil 2 secondary circuit- insufficient ionization" Since I was at Autozone, I figured I would just replace the plugs for #2 until I can get the others changed. That way the CEL would be off once those plugs were changed.

Well, the boot got stuck on one of the plugs on #2 as well, and this one wouldn't come out at all. It kept tearing and I decided to just take it to a shop and have them do it since I have torn the boot so bad it was halfway down the plug hole, and I couldn't get to it anymore. I put everything back together and drive home (~2 miles). I check the codes when I got home and it was P2305 and misfire for #2 (expected since there was basically no connection b/t the plug and coil since the boot was torn so bad).

Now, today, I have a shop change the plugs and both boots on #2. They charged like $54 for parts and labor, which wasn't too bad. But when they put it back together, the tech called and said it is running the same.

I pick it up and go home (~1/4 mile if that) and check the codes. Now it is just P2305 and no more misfire since the plugs and boots were both changed. I swap the coil for #2 with another coil to see if maybe the coil went bad. No luck, still P2305.

Now I am at a loss. The plugs and boots are both new for cylinder #2, and I swapped the coil to see if it would follow to a new cylinder with no luck and I still get P2305 for cylinder #2.

My next step is test the two wires going to the coil with a multimeter to see if maybe the wiring went bad, but that just seems unlikely (but possible I guess), but I can not do that until tomorrow.

Anyone else have ideas? Sorry for the long post, I wanted to get all the info and back story out there to keep from being told to do things I already did.

2005JGC 01-23-2012 04:41 PM

Re: Need some troubleshooting help with P2305
 
I would check the connector verify your pins are in good shape, check the wiring right there too... What all did you do from it running fine to __insert what you did here__ to starting it and it running like crap.

Typically the coils are low side drivers meaning there is power sitting there (likely from the ASD) and the pcm gives it ground when it wants to energize the coil. so your going to want to check for power and off the top of my head I am not sure if you will be able to get a test light to fire (possibly an LED test light would help) but if you put a testlight to the B+ post then to the pcm controlled ground circuit and start the car it should flash. I would suggest unplugging the injector on that cylinder while doing these tests and for any further driving you do until its fixed as it will just be dumping fuel into the exhaust and melt down the cat due to the misfire.

99formulam6 01-23-2012 04:53 PM

Re: Need some troubleshooting help with P2305
 
The only thing I did was:

1. Replace EGR

2. Disconnect connectors on all driver side coils

3. Remove bolts from all driver side coils

4. Start to remove driver side rear coil, but stopped when boot tore off

5. Tightened all coils

6. Reconnected coils

Then the next day, I replaced the boots on the driver side rear coil. When I went to leave the parking lot, is when the CEL stayed on after clearing the codes from the driver side rear coil (since boot was torn). So I checked the code and it was P2305.

99formulam6 01-23-2012 04:56 PM

Re: Need some troubleshooting help with P2305
 
Oh, I checked the pins and they looked alright. The wiring goes into the black loom after maybe 2'' or so, but the part I can see looks fine.

I planned on using a multimeter to check the wires going to the coil. I was going to put one lead on the B- post and the other on the wires to the coil (one at a time). I was going to do it on a good coil first to try and get a baseline and then go to the #2 coil.

2005JGC 01-23-2012 05:06 PM

Re: Need some troubleshooting help with P2305
 
Just keep in mind while your doing this, without the vehicle running, the asd will not remain on, just keep that in mind ;)

also I would suggest pulling those plugs (easy enough cylinder right) and inspect both plugs for proper gap and any cracks in the porcelain.

You may also consider just trying a battery disconnect... see if wiping the memory clean and trying again if maybe its just some stupid software glitch.

99formulam6 01-23-2012 05:22 PM

Re: Need some troubleshooting help with P2305
 
I thought about the plugs, but it was doing it before new plugs were put in. What would be the odds that it was the plugs in the beginning, and still the plugs after they were replaced? I am going to pull them tomorrow to check since it is easy enough.

I loaded in a new tune with the diablo to see if that would help. No dice.


I also have been reading the service manual and have a few questions..
Quote:

Possible Causes
(A15) ASD RELAY OUTPUT CIRCUIT
(K85) COIL CONTROL NO.2 CIRCUIT OPEN
(K85) COIL CONTROL NO.2 CIRCUIT SHORTED TO GROUND
COIL ON PLUG
PCM

Diagnostic Test
1. ACTIVE DTC
Ignition on, engine not running.
With a scan tool, read DTCs.
Is the DTC active at this time?
Yes >> Go To 2
No >> Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

2. (A15) ASD RELAY OUTPUT CIRCUIT
Turn the ignition off.
Disconnect the Coil on Plug harness connector.
Ignition on, engine not running.
With a scan tool, actuate the ASD Relay.
Using a 12-volt test light connected to ground, probe the (A15) ASD
Relay Output circuit in the Coil on Plug harness connector.
Does the test light illuminate brightly?
Yes >> Go To 3
No >> Repair the open or short to ground in the (A15) ASD Relay
Output circuit between the IPM and Coil harness connector.
Perform the POWERTRAIN VERIFICATION TEST. (Refer
to 9 - ENGINE - STANDARD PROCEDURE)
NOTE: Stop All Actuations.

3. COIL ON PLUG RESISTANCE
Turn the ignition off.
NOTE: The following resistance measurement should be taken at 70-80 F.
Measure the resistance of the Coil on Plug.
4.7L and 3.7L Primary Ignition Coil resistance is 0.6 to 0.9 of an ohm at 77F (25C).
5.7L Primary Ignition Coil resistance is 0.558 to 0.682 of an ohm at 77F (25C).
Is the resistance within the given specification for the Ignition Coil being tested?
Yes >> Go To 4
No >> Replace the Coil on plug.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

4. IGNITION COIL
Using a 12-volt test light connected to a 12-volt source, probe the
(K85) Coil Control No.2 circuit.
Crank the engine for 5 seconds while observing the test light.
What is the state of the test light while cranking the engine?
Brightly blinking.
Replace the Coil on plug.
Perform the POWERTRAIN VERIFICATION TEST. (Refer
to 9 - ENGINE - STANDARD PROCEDURE)
ON constantly.
Go To 5
OFF constantly.
Go To 6

5. (K85) COIL CONTROL NO.2 CIRCUIT SHORTED TO GROUND
Turn the ignition off.
Disconnect the C2 PCM harness connector.
Measure the resistance between ground and the (K85) Coil Control
No.2 circuit in the Coil on Plug harness connector.
Is the resistance below 100 ohms?
Yes >> Repair the short to ground in the (K85) Coil Control No.2
circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer
to 9 - ENGINE - STANDARD PROCEDURE)
No >> Go To 7

6. (K85) COIL CONTROL NO.2 CIRCUIT OPEN
Turn the ignition off.
Disconnect the C2 PCM harness connector.
CAUTION: Do not probe the PCM harness connectors. Probing
the PCM harness connectors will damage the PCM terminals
resulting in poor terminal to pin connection. Install Miller Special
Tool #8815 to perform diagnosis.
Measure the resistance of the (K85) Coil Control No.2 circuit from the
Coil on Plug harness connector to the appropriate terminal of special
tool #8815.
Is the resistance below 5.0 ohms?
Yes >> Go To 7
No >> Repair the open in the (K85) Coil Control No.2 circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer
to 9 - ENGINE - STANDARD PROCEDURE)

7. PCM
NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal
push out. Repair as necessary.
Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and
Ground circuits.
Were there any problems found?
Yes >> Repair as necessary.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No >> Replace and program the Powertrain Control Module per Service Information.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
Ok, so.

#1 - Yes the DTC is on

#2 - I don't know how to do that since it says use the scan tool to activate the ASD.

#3 - What points am I testing the resistance between?

#4 - Simple enough to test...

#5 and #6 - I am hoping it will stop here and not go to #7 since that step is for the PCM. But the schematic isn't detailed to show the K85 control circuit if I need to repair it.


I am a tech in the Navy, but our schematics are a little different than these...

2005JGC 01-23-2012 07:17 PM

Re: Need some troubleshooting help with P2305
 
You know the asd circuit is not going to be the fault (ok the circuit might) but it wont be the circuit failing as a whole because the other injectors and coils are working (all powered by the ASD). You know its not the coil pack because you swapped cylinders (good call btw). So your looking at PCM or circuit integrity to that specific cylinder. Obviously start with circuit integrity, basically just as I previously suggested, the testlight to the B+ terminal and probe the ground circuit while the vehicle is running your testlight should flash, if it doesnt this means one of a couple things, the pcm driver is not functioning, OR the wiring is open or shorted before the pcm. If its shorted to ground (ohm test would be great for this) then your going to fry your coil pack because its basically commanding the coil pack on all the time ;)

cliffs notes

Jeep running,
with the test light on B+ measuring the ground you should get a flash, on the B+ circuit with the testlight to ground you should have constant power. from there go to whichever side of the circuit is not operating properly.

measuring the coil resistance would just be across the 2 pins at the coil, not really important if you have swapped coils because this is just going to pinpoint a faulty coil pack.

99formulam6 01-23-2012 07:21 PM

Re: Need some troubleshooting help with P2305
 
Quote:

Originally Posted by 2005JGC (Post 559021)

cliffs notes

Jeep running,
with the test light on B+ measuring the ground you should get a flash, on the B+ circuit with the testlight to ground you should have constant power. from there go to whichever side of the circuit is not operating properly.

measuring the coil resistance would just be across the 2 pins at the coil, not really important if you have swapped coils because this is just going to pinpoint a faulty coil pack.

Alright. In my line of work, we don't use test lights, only multimeters (Fluke 87 True RMS to be exact), so can you clarify the steps and the B+ stuff. Do you mean positive from the battery? Or is B+ a location on the connector?

2005JGC 01-23-2012 09:48 PM

Re: Need some troubleshooting help with P2305
 
I also use a Snapon True RMS meter of my own at work but for simple circuit testing especially driver circuits nothing beats a good ol' testlight and I would suggest picking one up. One of my FAVORITE tools that I would go sell my body if mine broke and I didnt have money to get another one right away is my powerprobe... probably much more expensive than you would want to spend but a VERY useful tool!

B+ is battery positive, anywhere you will get potential battery voltage (battery, alternator post, starter. Hooking a testlight to the + battery post it will light up the testlight when it sees ground. So considering its a ground side driver you want to make sure it is doing its job, so testlight clamp to B+ (or your meter lead for that matter) then to the ground circuit at the coil connector. With the vehicle running your meter should pick up battery voltage on and off (light flashing as indicated in the service info you posted). If the light flashes (or your meter sees the on/off voltage) then your ground side is good and you likely have an open in your power side... to check this the testlight clamp or meter lead goes to the B- (negitave battery post) and touch the other pin in the connector, with the vehicle running it should be constant 14v. In theory once these steps are done you should have an idea of what your problem is. This is pretty much covering everything that the circuit primary circuit needs to operate.

99formulam6 01-24-2012 02:20 PM

Re: Need some troubleshooting help with P2305
 
Thanks for all the help.

I got it figured out today. Turns out the connection wasn't being made, so it fixed it up and all was well.

I was about to lose my mind though since I went through all the troubleshooting and the coil was fine, and the circuit was good too.

2005JGC 01-24-2012 02:46 PM

Re: Need some troubleshooting help with P2305
 
Not a problem, glad you got it sorted out!


All times are GMT -5. The time now is 08:52 PM.

Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Copyright 2012 - JeepGarage.Org
The Jeep Grand Cherokee Owners Community