I need some specific information on a 2001 4.7L Dodge Dakota, can someone help?

[84TSiGuy]

Note Truck is a 2001 model. Also since his has 4 o2 sensors 2 pre and 2 post I'm fairly sure it's a California model.


So it's a wiring issue. I need to know the pin# on which plug of the PCM/ECU are the signal input from the pre-cat O2 sensors. I have a manual and it looks like on the wiring diagram it's pin 24 and 25 of the 3rd plug which is the closest to the firewall. The trucks not getting a signal from any of the O2 sensors, but I have checked the post and 1 of the pre cat sensors and they are generating a 0-1v signal when heated with a torch so they're not dead. So I'm lead to believe it's a wiring issue and rather than try to isolate the exact part of the harness that's the issue, and considering the post cat sensors as I understand it are just there for verifying the cats are working / emissions and not fuel adjustments the owner doesn't care (my friend) nor do I. But the pre cat sensors signal is important to making fuel adjustments so that we do care about and are just going to run a new signal wire from the harness O2 sensor plug to the ECU/PCM pin's.

Also which pin goes to which cyl bank? Also, note we're doing this because Dodge apparently doesn't have a single engine harness left in inventory, anywhere in the country.

 

[dudeman2009]

The dakotas have the same PCM as the full size ram. Thats not the issue, the issue I have, my 01 manual doesn't list the 4.7 as an option, so the pinout may be slightly different than what I have, so verify wire colors before doing anything.

Everything is off the PCM connector as follows.

PCM Connector C1

Upstream O2 sensor left bank
Pin 24, tan/white wire
Upstream O2 sensor right bank
Pin 26, light green/red
Sensor ground
Pin 4, black/light blue

You'll need to tie both sensors into the ground pin, then tie the corresponding sensor into the other two pins. I'd suggest running the wires along the harness to the best of your ability and labeling them as to what they do so in the future its not a mystery. Metal punch tags work great, but if not, paper tags written on with pen then covered in either clear coat, or a thin layer of epoxy will also last a long time under engine bay conditions.

Good luck.

 

[84TSiGuy]

What i'm seeing in a Hayness manual (all we have to work with) is C1 pin #24 LG/R (assuming Light green / Red) and #25 O/T Orange? / Tan?

I see it shows another wire in the diagram that ties to the other sensor and seems to be the common ground? DG/R (dark green? / red) which goes to the upstream O2 sensor relay, where ever that is. You mention a ground pin though?

Here's the section of the diagram I'm working with. Note: it only shows 2000yr model not sure if it ever changed though the early years.

 

[kad]

Note Truck is a 2001 model. Also since his has 4 o2 sensors 2 pre and 2 post I'm fairly sure it's a California model.

So it's a wiring issue. I need to know the pin# on which plug of the PCM/ECU are the signal input from the pre-cat O2 sensors. I have a manual and it looks like on the wiring diagram it's pin 24 and 25 of the 3rd plug which is the closest to the firewall. The trucks not getting a signal from any of the O2 sensors, but I have checked the post and 1 of the pre cat sensors and they are generating a 0-1v signal when heated with a torch so they're not dead. So I'm lead to believe it's a wiring issue and rather than try to isolate the exact part of the harness that's the issue, and considering the post cat sensors as I understand it are just there for verifying the cats are working / emissions and not fuel adjustments the owner doesn't care (my friend) nor do I. But the pre cat sensors signal is important to making fuel adjustments so that we do care about and are just going to run a new signal wire from the harness O2 sensor plug to the ECU/PCM pin's.

Also which pin goes to which cyl bank? Also, note we're doing this because Dodge apparently doesn't have a single engine harness left in inventory, anywhere in the country.

I recently sold my '01 Dakota, but I have a PDF copy of the dealer service manual. It has the 4.7 listed, s that was what I had in mine. If you PM me an email address I'll send t to you.

-K