P1689 P0215 assistance

[JHFIII]

Update to say that I got it running. The VP44 did indeed need to be replaced. With the relay bypassed it was only pumping lift pump pressure out of one injector line. The old one couldnt even be turned by hand, something definitely bound up in there. A little dab of yellow paint on the new vp44 key was definitely a big help to get it lined up right. Very happy to have it running.

 

I still havent resolved my p0215 code, and I can only start it with the relay bypassed, but at least it roars once again.

All signs say is has to be the brown white between the PDC and ECM.

 

These are the results of the p0215 diagnostic:

1)Fuel pump relay 85(gd) to batt voltage =12v

2)Relay is good 75ohm

3)ECM 30/49 to batt voltage=12v

4)ECM 36 to relay 86 .2ohm

5)Relay 86 to G100 ground = 65ohm

 

Im only getting about 8V from the ecm to relay 86, with the igntion hot.

The brown /white from end to end reads .1ohm.

The brown/white to ground does not register a reading on the multimeter. Im not sure what that means.

Ive been hesitant to tap the brown white at the ecm and then the pdc connector and run an overlay wire to see if that fixes it, until I was absolutely certain (which Im still not, but I have a hard time blaming the ECM since its doing nothing else to make me think its on the fritz).

Does anyone know if its possible to fish a new wire through the ECM loom? Or am I just better off running it on the outside. The last thing Id want to do is screw up other wires in the loom. 

Thanks guys

 

[Dieselfuture]

3 hours ago, JHFIII said:

Does anyone know if its possible to fish a new wire through the ECM loom? Or am I just better off running it on the outside. The last thing Id want to do is screw up other wires in the loom

I'm sure it's possible but I would just run it on the outside then you know what it's for, I'm guessing that's for your lift pump right. some people just bypass ECM all together and run lift pump off a toggle switch through a relay, the only problem with that I heard off is safety in case of an accident. That and forgetting to turn it on or off, maybe get a toggle with LED built into it.

Edited November 1, 2017 by Dieselfuture

[Mopar1973Man]

7 hours ago, JHFIII said:

5)Relay 86 to G100 ground = 65ohm

 

Too high... I would chase that ground connection. That should be 0 Ohms. So it might not be pulling the relay closed all the way. 

[JHFIII]

5 hours ago, Mopar1973Man said:

 

Too high... I would chase that ground connection. That should be 0 Ohms. So it might not be pulling the relay closed all the way. 

Should that reading be taken with ignition on or off?

I read the #5 step as meaning that I should have exactly 100 ohms, but sounds like I'm mixed up on that. 

Does ECM sending 8volts through the brown/white, ignition on sound correct? (measure with the ecm harness connected, igntition on)

I have to check my notes, but I believe I measured the g100 gnd connector (disconnected) to relay 85 and got .1ohm.

My confusion is that the wires all appear to show continuity, but something gives.

For the record, I did clean g100 thoroughly. Once I got a surface rust and crud off , it actually looked pretty secure and clean.

[Haggar]

JHF,

 

If you were actually checking 86(this is the ECM output to fire the relay) to ground (ignition off.... ignition on would/should blow your meter) you could get a couple different readings.  with the relay in the socket, you would read resistance through the coil which should be in the range you said.  If you did it with the relay removed, you are reading backwards through the ECM and power supply.... it will be an odd reading.

 

Where did this diagnostic list come from?  I can't find it in my manual.  I would like to read what/why they are looking for.

 

I have attached the FSM page for the relay. 

 

To diagnose this system, I would:

1) remove relay. 

2) with the key on, put the black meter lead to ground (a good ground) and put the red in 86.  You should have 12v.

3)  have someone turn the key off while reading this.  The 12v should go away.  recycle the key on. it should come back.

4)move the red lead to cavity for 30.   This should have 12v whether the key is on or off. 

5)make sure key is off.  put meter on ohms.  touch red and black probes to each other.  This should read about 0.1 ohm or so.

6)put black lead on good ground, put red lead in 85.  You should have about 0.1ohms or so again.

7) Disconnect the wiring harness from the VP 44. 

8) with the black placed in 87.  put the red on terminal 7 (red / light green) at the injector pump.  this should read 0.1 ohm or so.

 

You have now confirmed that the

1) ECM is outputting 12v when it is supposed to.

2) fuse 3 is ok.

3) the wire between 85 and ground is good. (this will let the relay shift when commanded)

4) the wire between 87 and the injector pump is continuous.

 

The only thing we have not proven is that the VP44 is "seeing" the signal sent.  But if all the above checks out, it should be close.

 

The only other test we could do is put the relay back in and check Terminal 7 to see if it gets 12v.  but that would require the VP44 be disconnected, and it is possible that will throw other codes.  (if needed we will talk about how to set up a back probe.... but that is scary for weather proof type connectors.) 

 

HTH

 

Hag

 

 

2001 FSM Ram 8w-30-37.pdf

[JHFIII]

Thanks for the reply Haggar,

The testing referred to are Mopar1973Man's diagnostics

 

I have done most of the FSM type stuff. I am going to run through it again this evening and see what I come up with.

I know this is something that staring me right in the face, and Im just not seeing it.

[Haggar]

JHF,

 

Thanks for the link.   Step 5 exactly "100 ohms" is not important.   The reason is:  You have both ends of the wire disconnected.  You are then testing that wire to ground, looking for a short in the wiring.  When they say "greater than 100 ohms" this goes to infinity and even open circuit.  (it should be an "open circuit"  That wire should not go to ground anywhere.)  the technical writer was trying to compensate for technicians with poor troubleshooting skills, improper meter set up etc. 

 

It looks like in an earlier post  you say you read  (with ECM disconnected and relay removed) from the socket for pin 85  to ground less than 100 ohms. (you have shown a couple different readings there.) 

 

This is a big part of the problem.  (My meter reads O.L. when the leads are not touching.) with relay removed and ECM disconnected  when you measure from cavity for 86 with the red lead, and the black lead on the negative battery terminal you should see O.L. or whatever your meter reads with the leads not touching anything.  The brown/white wire should NOT be touching ground anywhere.... If you see any other reading than O.L. it is touching ground and is wrong.  (you will find the insulation on the wire is rubbed through somewhere.)

 

HTH

 

Hag