Strange p1689 code with fuel knock

[02isb47redana60]

Hey there so I’m a noob to this forum but not the cummins scene. I have utilized this forum for tons of info in the past with great success... until now I’ve never not found the answer. Long story short I installed a quadzilla adrenaline in my 02 2500. 10 seconds after starting the truck started smoking(so bad the fire dept was called by 3 neighbors) and developed an intense fuel knock. Contacted quadzilla and sent the module in, they confirmed it was a dud and replaced it. The iquad was claiming with the truck off that it made 42psi of boost off the map sensor(replaced the map with a cummins sensor as per Marco at quadzilla recommendation when the original sensor was fine)and that the egt was over 1800 degrees with out even installing the egt probe. However I uninstalled the entire adrenaline and the fuel knock persisted. Did the bluechip vp44 diagnostic and had a bad vp44. Install a new one, and still have a bad fuel knock, with a p1689 code that once deleted returns immediately without even starting the truck. I have a steady 12v power supply on pin7 of the injector pump harness. Good fuel pressure off a raptor pump. Waiting on a break out box to see if the new injection pump is bad or if the problem is else where. Biggest issue is this is my only company work truck and it tows my wood chipper(own a small tree service) any input appreciated

[Mopar1973Man]

P1689 is a communication problem between ECM and VP44. There is a CANBus + and - leads. You need to ohm from end to end should result in <5 ohm, over 5 ohm signal is degrading. Then same wire to ground this should result in infinite ohms. Short to ground is bad. 

[02isb47redana60]

Thank you for responding! Where are the can ya +&-  leads at sir? Nothing showed on google

[Mopar1973Man]

[02isb47redana60]

Thank you! I can read diagrams somewhat well, just to confirm I’d be checking the ohm reading on the data link to injection pump or #23 on the ecm? I attached a pic of what the iquad was stating after the first start up after install. Just got off dad duty so getting in the garage now! I initially purchased the quadzilla due to all your write ups and available tunes for purchase, once I get the truck squared away I will reinstall the quadzilla and purchase a few times and also make a few of my own. Thank you man. Also I’m running into a wall when trying to complete my profile? 

[02isb47redana60]

So I’ve probed around and I’m still at a loss. Any input appreciated deeply!!!

[02isb47redana60]

So I received a break out box yesterday and plugged it in. Truck won’t even try to start. When I reinstall factory FPCM harness truck starts and puts out white smoke. Sounded ok so after 30 seconds I tap the accelerator and it starts to stumble and knock. Vp44 is brand new. What would cause this??

[02isb47redana60]

On 10/26/2019 at 6:06 AM, Mopar1973Man said:

P1689 is a communication problem between ECM and VP44. There is a CANBus + and - leads. You need to ohm from end to end should result in <5 ohm, over 5 ohm signal is degrading. Then same wire to ground this should result in infinite ohms. Short to ground is bad. 

So unfortunately I was in an area with a fire and nearby lost my home and truck, the fire was stopped 100 feet away. Finally back at it, can you elaborate on when you say short to ground is bad. Have the harness off and testing wires now. Thanks in advance, I’ve learned so much off this forum.

[kzimmer]

With the communication cable isolates from the pump, grab your multimeter and check for Ohms between either of the two wires, separately, to ground. You are looking for a big number, aka a lot of resistance. Or, preferably, the meter might say O L.

[02isb47redana60]

On 11/7/2019 at 3:55 PM, kzimmer said:

With the communication cable isolates from the pump, grab your multimeter and check for Ohms between either of the two wires, separately, to ground. You are looking for a big number, aka a lot of resistance. Or, preferably, the meter might say O L.

Thank you man! These power outages and fires have been a night mare! I will test these two wires tomorrow. Also, I would be testing resistance from end of wire to end of wire or with it still plugged into the ecm? Sorry electrical is my weak point, more of a glorified r&r guy. In the event I do not see a high number does this condemn the ecm?

[kzimmer]

I think you are testing the cable itself for damage, so it's best that it be unplugged from the VP44 and ECM. Someone that has performed these tests may say otherwise, but that's how I'd do it if I was looking for a short to ground. 

[02isb47redana60]

Thank you so much dude. So everything checked out, even checked communication to the pcm from the ecm and the ecm is bad. Just ordered a new one through flagship(900) hopefully it gets here soon so I can get back to work