Manually switching on fuel pump

[Ravewolf]

Just curious, but what would happen if one were to bypass the ECM and install a switch to turn on the fuel pump? Mine works fine, but I was always curious about it.

[Silverdodge]

nothing common to do it that way

[Mopar1973Man]

If you have an accident and the fuel pump will continue to pump. I highly suggest having the ECM repaired so when the tach hits zero the fuel is shut off. After being to several accident scenes in not pretty when a fuel pump continues to pump fuel with a live fire. 

[dripley]

I wouldn't do it unless I just had to. But would not leave it that way for the reasons above.

[Ravewolf]

Well, mine still works fine(still not running, usps screwed WiscoRedkneck on my injectors) I was just curious because my friend and I were talking about swaps and such, and how someone would run a pump in that situation. He has a 79 ford truck and I joked about stealing it and swapping my 24v into it, then it just went downhill from there. 

Also, the 24v can be ran without the dodge pcm, I found a website that shows how to do stand alone wiring in case anyone had any ideas. Just food for thought for ya'll. 

[Mopar1973Man]

You can run a 24V ISB as a standalone with the ECM. 

 

Problem.

 

If you want diagnostics or work OBDII port you need both the PCM and the instrument cluster. The PCM starts the CCD Network bus. The Cluster is what gives bus bias to the CCD Network. If you do go the stand alone you completely with diagnostic information. Yeah there is the CANBus but its limited in what it can do being the diagnostics was based more so in the CCD Network side. Hence why weird things like engine coolant temperature only report to 204 then drops to -40 on the CANBus where the CCD bus works correctly. 

 

You could never run a Smarty or any kind of OBDII port tools on a standalone Cummins.

 

As for the lift pump the ECM will still control the lift pump. Just controlled by tach signal. If you happen to wreck the tach hits zero the ECM cuts power to everything. As for starting and run its behaves like normal. 

 

Edited April 29, 2019 by Mopar1973Man

[Ravewolf]

On 4/29/2019 at 2:46 PM, Mopar1973Man said:

You can run a 24V ISB as a standalone with the ECM. 

 

Problem.

 

If you want diagnostics or work OBDII port you need both the PCM and the instrument cluster. The PCM starts the CCD Network bus. The Cluster is what gives bus bias to the CCD Network. If you do go the stand alone you completely with diagnostic information. Yeah there is the CANBus but its limited in what it can do being the diagnostics was based more so in the CCD Network side. Hence why weird things like engine coolant temperature only report to 204 then drops to -40 on the CANBus where the CCD bus works correctly. 

 

You could never run a Smarty or any kind of OBDII port tools on a standalone Cummins.

 

As for the lift pump the ECM will still control the lift pump. Just controlled by tach signal. If you happen to wreck the tach hits zero the ECM cuts power to everything. As for starting and run its behaves like normal. 

 

Tha gauge situation could be taken care of by manual gauges, right? Also, doesn't quadzilla plug into the canbus only? In theory all it needs is 12 volts to run and it could work on a standalone setup, right? 

I'm not swapping anything right now, I am just doing research. 

[Mopar1973Man]

Just now, Ravewolf said:

Also, doesn't quadzilla plug into the canbus only? In theory all it needs is 12 volts to run and it could work on a standalone setup, right?

Yes, this is true. Just be aware that Quadzilla can't read error codes. 

 

1 minute ago, Ravewolf said:

Tha gauge situation could be taken care of by manual gauges, right?

Mechanical gauges would work or even electric gauges. But The ECM must till be hooked up to all the factory sensors. 

 

The other thing is to be aware the grid heater will not shut off like they are designed. They require speed signal from the ABS computer so when the vehicle is over 25 MPH it cuts the grid heaters. Then grid heater post-heating is controlled by the battery temp sensor from the PCM. So grid heater functions might have to be manual thing.

 

 

 

[Dieselfuture]

6 minutes ago, Mopar1973Man said:

Then grid heater post-heating is controlled by the battery temp sensor from the PCM. So grid heater functions might have to be manual thing.

And the charging of the batteries, you may have mentioned that already.