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P0201-INJECTOR #1 CONTROL CIRCUIT

13K views 10 replies 3 participants last post by  Angelo The Christ  
That's a confusing set of tests. Throw that in the trash.

Disconnect the #1 fuel injector pigtail/plug. Measure the two pins on the fuel injector with a multimeter, it should have 10 to 15 ohms of resistance.

If the injector is good, test the harness:

Driven side:

Test between pin 2, Brown/yellow wire, on the injector plug and pin 3 on connector C102. Expect around 1 ohm or less.

Test between pin 3 on connector C102 and pin 13 on connector C1 on the PCM. This is also a brown/yellow wire. Expect roughly 1 ohm or less.

Plug C102 back together. Check between C1(pin 13) and injector #1 connector (pin 2). There should be 1 ohm or less.



Power Ground Side:

Test between pin 1, brown/white wire, on the injector plug and pin 1 on connector C102. 1 ohm or less expected.

Test between pin 1 on C102 and pin 3 on Connector C4, there should be 1 ohm or less. This one is probably useless to test, a break here would cause all of the injectors to fail.

Reconnect C102. Test between pin 1 on the Injector #1 plug and pin 1 on C102.



Injector plug/harness test:


Reconnect the injector plug onto the #1 injector. Now test between pin 1 (brown/white) and pin 3 (brown/yellow) on C102. There should be 10 to 15 ohms of resistance. If not, you probably have a bad pin connection in the injector plug.



Here's how to read the Schematic.
Image

Also, the arrows tell you the orientation at connectors.

---< this is a male plastic plug, but with female/socket pins.
---> this is a female plastic socket, but with male pins.

Pins --->>--- Sockets



Here's one with notes for you
Image




Here are the relevant Schematics of the connectors:
Injector connector
Image



C102 Connector
Image



C1 connector
Image



C4 Connector
Image





Location of connectors:
Image


Image


Image

Source: 02 RGE; 2002 RG/RS Platform Chrysler Factory Service Manual; Property of CHRYSLER Corporation
 
Good evening my friend and happy blessed Wednesday!

I disconnected the #1 fuel injector pigtail/plug. I measured the two pins on the fuel injector with an Innova 3300, it gave me these results
.
Okay, so the injectors are all good. 12.5~12.6 ohms is spot on.

Next would be to test the injector harness. It only goes between connector C102 and the six injector plugs.

Image




You need to plug all of the injectors back in, and on the engine side of C102, male plastic plug with female socket pins, test resistance between pin 3 and pin 1 to see injector #1. It should be close to the same resistance as the injector alone, maybe 12.5 to 13 ohms. You could also test the other injector wires while you're in there. Pin 1 has the wire that is Brown with a White stripe. Pin 3 has the wire that is Brown with a Yellow stripe.

Pin 1 to pin 3 = Injector 1
Pin 1 to pin 4 = Injector 2
Pin 1 to pin 5 = Injector 3
Pin 1 to pin 6 = Injector 4
Pin 1 to pin 8 = Injector 5
Pin 1 to pin 9 = Injector 6

Image
 
In the video i sent you i was using an Innova 3300 to check the resistance of all 6 fuel injector terminals on OHM .200.

Can i use this tool for the next test on the picture?
Yes. If the injectors are plugged back in, and you test between pins on the C102 connector, it'll be exactly the same as measuring the injectors, except you're measuring the injectors through their wiring. So you should get almost the same measurement, maybe slightly higher.

Pin 1 and pin 3 on C102 are directly connected to the injector pins through the wiring harness.

Your check engine light code says the computer is getting a measurement of infinite ohms to the injector or close to it. If the injectors are good, then it must be a broken wire or bad connection in a plug. Watching the video you posted, when your multimeter sees infinite ohms, aka open circuit or no connection, it shows "1 . "
A reading of infinite or " 1 . " would likely be the problem you're searching for, though it could also just be a really high resistance reading above 15 ohms if there's a poor connection somewhere.


You could also use the symbol next to the 200 ohm to test wires, it measures continuity. The symbol looks like an arrow touching a plus sign, –>+
Continuity just means that there's a good circuit or connection. I'd probably measure the resistance in this case since you're also looking at the injector through its wires, but if you were just testing the wires alone continuity would be good. Most meters will beep loudly when they measure good continuity in the continuity mode.
 
If the harness is unplugged and the van is off, there's no risk of frying anything. You should probably have the battery disconnected anytime you are unplugging or checking the harness to be extra safe too.

There's a good chance that the probes are too big to fit into the sockets, you can either stick a paper clip or short piece of stripped wired into the socket to be able to read it with the probes.

The polarity of the probes should not matter, black and red, testing this circuit for resistance/continuity.