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Discussion Starter #1
2007 Town and County 3.8
Van started missin and when I checked the codes I got p0202 and p0302 I install a new plug, new injector and checked all the wiring for cracks. Started the van and still have the same problem and same codes. Using a test light I checked for power at the connector where the main harness connects into the injector harness all injectors had power except number 2. Unplug the harness from the PCM check for continuity from the plug all the way to the injector and I have continuity. Is this a PCM problem ? Thanks for any info
 

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No power? Or no ground switching from the PCM? IIRC, all injectors get power directly from the ASD relay so if 1 injector has 12V (13.8V) present then all injectors should have 12V (13.8V) present on them. Switching happens on the low side with the PCM activating each relay by grounding the low side of the injector coil.

Hmmm... after a quick look at a schematic, if you broke open the connector and probed where I think you did then you were probing the low side of the injector which connects directly to the PCM? Should show 12V on each injector low side... until the PCM grounds that line to activate the injector. If you didn't see 12V on only one of the six injector lines going to the PCM, then you've likely got a problem (open circuit) getting 12V from the ASD relay and through that injector to your test point, or a short after the injector keeping the line grounded and the injector activated all the time. Probably not a short between ASD relay and injector coil as the fuse did not blow.

What you need to test for is whether that PCM line is being held low (on) all the time and, if so, whether or not the PCM is the cause of this constant short to ground. Was the injector harness connected to the PCM at the time when you tested or not? If the PCM was disconnected and you were testing on the injector side of the harness with your check light tied to a ground elsewhere, then that would likely rule out the PCM. If PCM was still connected at that time then short could be inside the PCM.
 

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Is this a PCM problem ? Thanks for any info

It may very well be so. The injectors on my 2002 have a common VDC+ and each individual injector is grounded by its own driver that is inside the PCM.

*now there was a member in one of the xxxikstan countries that had a similar situation but the availability of parts was a few months out. He reported a temporary work around where they tied that dead injector in parallel with another injector.

While this is not a recommended repair, it may be a possible emergency fix to get you off of Giligans Island.
MaryAnne
 

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Discussion Starter #4
I sould add I had the van running when I used the test light. I checked it at the connector that is just above the water pump where the main harness connects into the injector harness I checked every injector wire and had a light excepted the #2. Am I right to think #2 should have had power like the rest. Or could this be a ground problem the wire with no power is the brown with dark blue stripe
 

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Was test light wired from signal to a ground? Or 12V to signal?? From your description, I would assume signal to a ground...

Also, is your test light an older incandescent one or a newer LED?

If your test light is low power enough (LED) I would think you could test from 12V to signal while the engine is running, seeing how number 2 compares in that case. If there is a constant short there, I would think you'd have a brighter light than if the PCM is actually switching normally like the other injector control lines (Constant on versus pulsed). Not sure you'll even see the light in this mode with the short duration injector pulses; however, a constant short should light up nicely. To be on the safe side, I'd be careful to only apply 12V to test light while the engine is running so you know the PCM control circuit is powered. Other folks feel free to chime in on this...
 

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According to my 2005 service manual wiring diagram, Brown/DarkBlue (BR/DB) is indeed injector #2 control from the PCM.
 

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The 2005 wiring diagram shows:

Power From ASD: BR/WT (Pin 1, Shared Supply To All Injectors)
Injector #1 Control: BR/YL (Pin 3)
Injector #2 Control: BR/DB (Pin 4)
Injector #3 Control: BR/LB (Pin 5)
Injector #4 Control: BR/TN (Pin 6)
Injector #5 Control: BR/OR (Pin 8)
Injector #6 Control: BR/VT (Pin 9)

If you have a multi-meter, one simple check you could do with the van off (power disconnected to be extra safe) would be to disconnect the injector harness and check resistance from BR/WT to each of the control lines on the injector harness. If all is good on the injector harness side, I would think you'd see comparable resistance readings for each of the injector coils.

Other wires on that harness connector are:

Pin 2 (VT/BR): MAP Sensor Output Signal
Pin 7 (DB/DG): MAP Sensor Return
Pin 10 (PK/YL): Map Sensor Source
 

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Discussion Starter #9
UPDATE; I Just rechecked the BR/DB from the injector to the PCM and I had continuity but when I checked it with the test light nothing. Ran a new wire from the PCM to the main connector and the van is running like a champ again
 
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