It seems since I brought my truck into the dealer for the 3 cylinder high idle cold start enabling my grid heaters haven't worked. I see the wait to start light come on but the voltage doesn't change. I have to plug it in even at 0'C now or it won't start. Lots of white smoke for the first few minutes when I do get it running . Could there be another problem I'm missing maybe? Can a dealer possible program stuff to mess up or maybe accidentally delete my grid heaters somehow?

Any codes? sometimes when working on truck I knock the little wire to grid heater relay loose and they wont work. Of course when I do that I get a code.

Check your wiring for the grid heaters. See if the fusible links have failed. See if the any P0380 or P0382 codes.

These codes showed up in the order as follows. PCU 0500,1694,1693. ECU 0234,1693.

There is a smaller waste gate boost elbow installed.

One morning I had the check engine light stay on but it was gone when

I fired it up again.

What are the perameters for when the grid heater should come on and off

Found my answer: http://articles.mopar1973man.com/general-cummins/32-air-system/102-grid-heater

These codes showed up in the order as follows. PCU 0500,1694,1693. ECU 0234,1693.

 

http://articles.mopar1973man.com/2nd-generation-24v-dodge-cummins/59-obdii-error-codes/190-p0500-no-vehicle-speed-sensor-signal

 

http://articles.mopar1973man.com/2nd-generation-24v-dodge-cummins/59-obdii-error-codes/232-p1694-no-bus-message-received-from-companion-module

 

http://articles.mopar1973man.com/2nd-generation-24v-dodge-cummins/59-obdii-error-codes/165-p0234-turbo-boost-limit-exceeded

The P0234 is probably cause by a heavy foot and the smaller boost elbow. P0500 I heard is from spinning the tires and not really moving, not sure if that's totally true. But with the torque of these truck on icy streets it happens a lot .

Some times you get a condition where the rear axle is spinning but the front axle isn't moving then the ABS computer gets confuse and trips the P0500 code because how can half a truck but motionless and the rear half is moving 25 MPH. ABS computer can't compute that.

So I took it to the dealer this morning because I wanted them to check and make sure they never set something off. They told me it was my relays and it happens a lot ... I checked for codes as soon as I got back in the truck. Now it says PCU 0500,1694, 1693 and ECU 0382, 1693. Why wouldn't that show up before I gave it to them?

Double check your grid heater relay wiring. The trigger wires are just push on type.