[FIXED] 2009 Journey 3.5 L

DTC PO304 and PO204. Check Injector #4 using TL and it pulses so I reckon a good control by the PCM. Did a cyl drop test on #4 and no change as I unplugged the harness; swapped with adjacent coil#2 and it did not go with the swap so coil good. Placed it back to cyl#4. There seem to be no control fro the PCM. How do I go about testing the integrity of the wire (from the PCM to the harness)? I am afraid I might accidentally fry computer.

(I will scope injector to make sure it is working)

Thanks.
p.s. regarding the honda with EVAP vent problem, the canister had some blockages. Working well now !

So, only a 2 wire coil, must be not hard to check.

Does it get constant power by the Brown/Grey wire and TL lights connected to brown/grey, but TL doesn't flicker connected to Dk Blue/Grey wire, correct? But does TL light connected to Dk blue/Grey? Did you measure resistance of the coil?
If so you should check at the computer the same Dk Blue/Grey wire it should be a pulsing ground. You can only fry PCM if you connect this wire to battery positive directly although it can possibly monitor current draw and disable the driver but not shure. TL is a safe way and scope too.

robert.lesaca wrote: DTC PO304 and PO204. Check Injector #4 using TL and it pulses so I reckon a good control by the PCM. Did a cyl drop test on #4 and no change as I unplugged the harness; swapped with adjacent coil#2 and it did not go with the swap so coil good. Placed it back to cyl#4. There seem to be no control fro the PCM. How do I go about testing the integrity of the wire (from the PCM to the harness)? I am afraid I might accidentally fry computer.

(I will scope injector to make sure it is working)

Thanks.
p.s. regarding the honda with EVAP vent problem, the canister had some blockages. Working well now !

Hi Robert.

Perhaps the easiest way would be to plug a noid light into the injector harness and look for it to flash while running or during cranking. There are other methods though that are not to difficult.

If you disconnect the injector and check both pins of the pcm side harness, one side will be 12v the other side will be nothing. Now remember the wire that was not 12v. Plug the connector back into the injector. Back probe the pin that was nothing. If it no shows 12v, then you know the winding in the injector is good.

Next you can use a scope or a power probe or a dvom. Connect one side of the dvom to ground, and the other side to the back probe on the injector wire that wasnt 12v when disconnected. If you start the vehicle, you should see 12v and then ground. On a power probe you should see flashing between 12v and ground. On a DVOM you will probably see voltage lower than 12v because it is aliasing. You can then check your min max on the dvom and it will show you that you have your grounding taking place from the pcm. This verifies your pcm and wiring harness. If it shows a straight 12 volts without changing, do the same test at the pcm wiring harness. You may have an open in the wire between the pcm and the injector. If you have the same results at the pcm, replace it.

Usually what I will do in the shop is just swap injectors between adjacent cylinders. If the miss moves to the new cylinder, you know the injector is bad.

robert.lesaca wrote: p.s. regarding the honda with EVAP vent problem, the canister had some blockages. Working well now !

Sweet! :woohoo: The Snappy Troubleshooter came through on that one. I'm gonna go update that thread.

Like komobu mentioned, swapping injectors is an option, though I'm not sure you'll be able to get the rail up high enough to swap without removing the intake. I'd do some injector testing with your test light, given the P0204 code. If you find power and ground at the injector, then I'd suggest an ohm check of that injector. Not sure what the spec is, but I'd say anything higher than 17 ohms is a problem. Compare to another injector for reference.



FYI, I just had a '09 Charger in with a 3.5L for a bad injector. Electrically failed with higher engine temperatures, nearly identical codes. As for the lack of coil control, I think this recent thread may have an answer. chris.arriazola found that his Ram was shutting the spark off in response to a misfire, not just the injector. :ohmy:

Not sure if you're a Premium subscriber, but this newly reworked Chapter 3 video is relevant .

I did do a noid test along with a test light on KOER; couldnt disconnect the connector from inj. as I did not want to snap the lock. I will the other injector test you mentioned. What about the coil - it did not have an RPM drop when connector unplugged? impossible to swap injectors, Its a good thing cyl #4 in question is located right in front and accessible. Thank you for your quick response. I will update this thread...

Thanks Tyler...always glad to hear from you.

robert.lesaca wrote: What about the coil - it did not have an RPM drop when connector unplugged?

I believe that's because the cylinder isn't firing due to lack of fuel. You're not seeing an RPM drop because having spark in the cylinder won't matter if there's no fuel. Or, that coil is being intentionally shut off due to the misfire.

If you really wanted to be confident about the coil, you could remove it from the valve cover and use a test light to check for spark with the engine running. Do this quickly after startup, as the PCM may deactivate that driver. If you have spark, then I'd say the coil and wiring are OK.

Thanks Tyler...always glad to hear from you.

No problem! Let us know what you find.

Look what Mr. Eric O. got for you

Check out his actions. You can just short auto-shutdown relay 30-87 posts instead of using scantool to energize the circuit.

borntoroll wrote: Look what Mr. Eric O. got for you

Check out his actions. You can just short auto-shutdown relay 30-87 posts instead of using scantool to energize the circuit.

Just watched this over lunch! :lol:

isnt it a groundside? Arent you suppose to see 12V on both wire plugged in and when unplug the wire that changes from 12V to 0V is control wire. So when plugged in and both 12V then injector is good. I am now confused when you mentioned that when plugged in..."if no shows12V, then inj. wiring good"...

with KOER, harness plugged in, TL to batt (-), touched control and TL pulsing indicating PCM control. Now what confuses me is the coil. At the same time the injector is pulsing, coil#4 did not show signs of cylinder drop as I unplugged the connector. But when I swapped coil#4 with coil#6, cylinder drop test followed coil#4 thus coil#4 is good and it's connector bad.

hi...i do not mean to be rude butI just cant understand what you are trying convey. kindly rephrase your tech advise...thank you.

by the way, where is the PCM located?

robert.lesaca wrote: by the way, where is the PCM located?

Not positive, sir, I'd have to check that tomorrow.

isnt it a groundside? Arent you suppose to see 12V on both wire plugged in and when unplug the wire that changes from 12V to 0V is control wire. So when plugged in and both 12V then injector is good. I am now confused when you mentioned that when plugged in..."if no shows12V, then inj. wiring good"...

with KOER, harness plugged in, TL to batt (-), touched control and TL pulsing indicating PCM control.

hi...i do not mean to be rude butI just cant understand what you are trying convey. kindly rephrase your tech advise...thank you.

Sorry, I don't mean to be confusing! :blush: It sounds like you've verified injector control with the test light, good stuff. If the other injector wire can light a test light connected to B-, then that wire is good, too.

You're correct about this being ground side switched, and the voltages you should see on both injector wires with the engine not running.

coil#4 did not show signs of cylinder drop as I unplugged the connector. But when I swapped coil#4 with coil#6, cylinder drop test followed coil#4 thus coil#4 is good and it's connector bad.

Wait, the misfire moved with the coil? :huh: But I thought you'd already swapped the #4 coil with the #2 in the opening post... So now, with the #4 coil on the #6 cylinder, #6 fails the drop test? If that's true, then you've found a bad coil, and the injector code is a separate issue.

I mean no offense here, but are you certain about your drop test results? 'Cause I don't want to see you buy a coil for nothing!

good morning from snowy Toronto !

Thank you for responding...yes coil # 4 seem to be working good as evident by my swapping it with #6 coil. The PROBLEM on hand is the harness of coil#4 coming from the PCM - there is no control (even with coil #6 already swapped into cyl 4 and disconnecting the harness plug did not cause a change in RPM). I want to test wire from the PCM to the connector harness but I do not know where the PCM is. Also what kind of test should be done to avoid frying the coil driver?

Before I left for home I erased the fault codes, waited about half an hour and then restarted the car, let it warm up for a considerable time and the engine run with no misfire. We drove the vehicle around the block for a good 5-10 minutes without a problem. The misfire returned the following day. (In one of Pauls video, he mentioned about PCM intentional shutdown - could this be related?).

robert.lesaca wrote: Before I left for home I erased the fault codes, waited about half an hour and then restarted the car, let it warm up for a considerable time and the engine run with no misfire. We drove the vehicle around the block for a good 5-10 minutes without a problem. The misfire returned the following day. (In one of Pauls video, he mentioned about PCM intentional shutdown - could this be related?).

Absolutely could be related! I think the injector is failing intermittently (the P0204), and when it does, the PCM shuts down the ignition coil on the same cylinder. We usually don't see ignition coils to be shut off, only injectors, but it seems newer Dodge models are doing things differently. :silly: The failed injector I found on a newer Charger 3.5L only failed after a test drive and a hot soak, so it's not unusual for these things to come and go with temperature.

I want to test wire from the PCM to the connector harness but I do not know where the PCM is. Also what kind of test should be done to avoid frying the coil driver?

I'd suggest keeping it simple with the test light. While the car is running on all six cylinders, backprobe the coil connector and check for power and control (ground). If control is present, then your test light will flicker when connected to B+ on the control wire. Power should be steady, misfire or not.

There's no danger of frying the coil driver this way, as long as you use one backprobe at a time.

Borntoroll and Tyler -
just an update...I got back from the working on the vehicle earlier today and just did some basics. i revisited injector simply because: when I did an initial scan live date (I use CRP 229 by Launch) of injector #4 pulse width from a cold engine start yesterday, i noticed the counter making readings and then would abruptly indicate a 0 count and continue with its reading, obviusly some anomalies going on. But then I concentrated too much on coil#4 control as it showed no sign of drop test when i disconnected it (and then swapped with #6 which, did drop indicating good coil).

Anyway, long story short, KOER, probed control wire on injector 4 with (connector plugged in) and showed good power and ground as indicated by TL flicker. however on KOEO, i energize injector and no click of any sort. Just to be sure, did the same on injector 6 just to hear it click. so now i am confident injector bad; i believe there is an open on the injector (i did not bother to scope for a waveform).

now i am hoping that the PCM does an intentional shutdown of the coil when it sees anomalies with the injector. i advised owner to have injector replaced. (would you guys agree the situation as a fix?)...

thank you so very much once again.

Hi Tyler...i found a way to upload your pico waveform to this forum.
1. from your pico file, get the waveform you want to upload;
2. go select "Print";
3. click portion that say "Name" (right beside the "Properties" button) and change "Canon iP7200 series 200" to Microsoft Print to PDF" ; click OK;
4. it will take you to your windows folder; CLICK on folder you want to save the waveform in (or you can create another folder);
5. in the filename area, type in the title of the waveform you want (ex: bad injector honda .....etc);
6. press SAVE.
when uploading to the forum, click ADD FILE and it will take you to your windows folder, choose the folder and click on the title and click open.341

Here is an example of a 2003 honda accord exl waveform for a cam sensor bank1 PO341 code...both bank exhibited a difference in waveform. from your experience which one has the anomaly? or do they behave differently?

...ignore that portion that read 341 after the word open...

robert.lesaca wrote: now i am hoping that the PCM does an intentional shutdown of the coil when it sees anomalies with the injector. i advised owner to have injector replaced. (would you guys agree the situation as a fix?)...

100% agree, injector is gonna fix this one. Good work with the test light, BTW. A scope waveform would have been fun, but I think you proved the failure without it.

If it helps you (or anyone else following along), here's a couple captures I took off the Charger 3.5L with a P0206 and P0306. Yellow is a amp probe on the power feed fuse for the injectors and coils, green is connected to the #6 control wire. The super tall towers are the coils, the shorter ones are injectors. There's one missing because it's electrically open, and 0V on the control wire, indicating a complete open in the injector.



Then, I added a test light to the injector control backprobe. The green trace now shows a pulse where an injector current ramp should be, confirming PCM control.

Here is an example of a 2003 honda accord exl waveform for a cam sensor bank1 PO341 code...both bank exhibited a difference in waveform. from your experience which one has the anomaly? or do they behave differently?

Thanks for posting the way you got this to print! We get this question often from other Pico users - I might repost this later? Just to help others out.

As for your waveform, I'm definitely confused! This is a 2.4L engine, correct? 'Cause you have the scope notes down as bank 1 and bank 2. Did you mean intake and exhaust CMP signals?

Anyway, your waveforms look like nothing else I've found. Could you let me know which signal is intake or exhaust?

Owner is scheduled to have injector replaced this week. Once I hear from him, I will inform the forum ...