banyon

My grid heater light stays on about half the time. Anybody know what tells it to come on or off? It seems like it would be a temperature sender but I`m not sure. It couldn`t be good for it to stay on for mile after mile. Please help!

1-2-3

If the air is cold enough going into the intake it will stay on. Being on while driving won't hurt anything, and may be needed at times. Fill out your signature , so we can see where your at and what you got.

jumper

My grid heater dash light requires the key on-engine off to light. When first turning the key to run (but not starting), the GH is activated for little bit, then a relay audibly trips and the light goes out. I then start the truck.

After start up, I can sometimes hear the GH relay cycle, turning on the GH for a few seconds (and dash lights and headlights dim briefly if at idle). The GH dash light never comes on while the engine runs, however.

banyon

My truck is an 06. The coil light on the left side of the dash will come on at random. Sometimes after I`ve driven for 100 miles or more. If I unplug the wire that starts the relay an engine light come on. I forget what code it is but it`s low volts or something. A local shop told me to get the emc reprogrammed but the dealer doesn`t think it needs it. It must have a sending unit that checks temps. to know when to turn on or off. Example, it doesn`t come on in the morning when it`s 70 degrees outside, but does if it`s 20. Oh yeah 1-2-3, it comes on riding down the road even when its warm out. Thanks for the replies

ssandlin

I'd think the sensor would be at the same location as the grid heater, which is located between the intake horn and manifold. But I've been wrong before!

banyon

I looked again this morning for the sensor. I found it! If it`s the right one it`s towards the back of the intake. I`m going to swap it with one from my buddy`s truck & see what it does. If that fixes it I can buy it from Dodge for $195, cummins $73 or parts place for $60.

Joelds78

Did this fix your problem? I had the light come on and start dinging while I was driving, so I was wondering if it was the same issue.

banyon

I didn`t replace it yet. I`ve thrown parts at this truck so much that i`ve decided to take it to a shop that specializes in dodge diesels If he fixes it I`ll let you know what it was. My engine light (code PO 148) has been on so long it seems normal to see it. I`ve replaced lift pump, fca, rail pressure sender. It runs great for about five miles then has no power & smokes for about ten miles. Then it decides to run like new the rest of the day.I`ve had it at two dealers & they don`t seem to know what to do. Flame on but this great cummins has cost me more than I think a 6.0 ford would.

carl48

that is not where it is at you are looking at the map sensor. there are two codes associated with the heaters. but first how it works, the grid heater is a emission control and not needed to start the truck. the wait to start light always comes on regardless of temperature. this trains you to always wait to start. when the temp is below 55* the air temp sensor located on the filter box sends a signal to the ecm to activate the grids. the ecm then monitors the voltage drop to make sure the grid is working if it does not see the drop it sets a check engine code off. when you delete the grid heater simply do not wait to start and it will never set the code off once you have started the ecm compares the air temp and coolant temp to determine cycling and duration rate when the ecm calls for heaters it looks for coil current to make sure the solenoids are working if it does not see the current it throws a different code. most who delete just remove the fuse link and leave the solenoids connected we remove all wiring and solenoids and grid. we connect a 25 ohm resistor between ground and the green control wire to fool the ecm since we do this to all of our trucks new from the dealer i did not know there was a coil light on the panel for those out there that are stock does the coil light come on at the same time as grid cycle and where is the grid light located on the panel. back to your problem. i would remove the fuse link feeding the solenoids, it is a black wire located between the + side of battery and the solenoids by the battery box. just remember do not wait to start. with the coolant temp up it should never cycle if it is really cycling you are asking for some serious damage if the grid comes apart, if the grid in not cycling but the light says it is i think it is the ecm i would either take the bulb out or ignore it

banyon

Thanks for the advise. Yeah, I figured out I was looking at the map sensor. I unhooked the hot wire that feeds the grid solenoid until I can get it to a shop. I would delete it if that was my only problem but my engine light staying on all the time plus low power has me stumped. The light is on the left side of the instrument panel. It is orange & looks like a spring or coil. The thing that`s got me confused is that it will run good sometimes & no power sometimes. If it was a mechanical problem it seems that it would run the same. It seems to not be getting fuel but if my high pressure pump was bad it seems like it would be low power all the time. It feels like it`s defueling.Thanks again.

06RAM2500

Can't remove the bulb as it's part of the printed circuit. I know cause my 4x4 low light doesn't come on, and I went to check for a bad bulb. Was a total no go!!.

If the CEL is on and you got low power, chances are your MAP/IAT sensor is shot. It's messing with the grid heater circuit (GH light is on) and it's not sending the ECM any boost signal, or it's way off from what is should be (low power issue). Make sure that you don't have a P0237 set (MAP sensor voltage too low).

banyon

When the grid heater light comes on it doesn`t set a code. It will come on at random times, like two hours into a trip. The light still comes on even with the main hot wire unhooked. At first the truck would only run poorly in the morning but clear up. Now it seems like the hotter the outside temp is the better it runs.As the day gets warmer it run ok but still is low on power. The check engine light stays on all the time & PO148 code is always there. Would you try a new map sensor? I`m at a loss but thanks for helping me with it.

06RAM2500

The P0148 is a horse of a different color.

OTHERS DTC’S PRESENT
FUEL LEAKS
FUEL CONTROL ACTUATOR
FUEL PRESSURE SENSOR
CASCADE OVERFLOW VALVE
CHECK VALVE DAMAGED OR BLOCKED
FUEL RETURN LINES OBSTRUCTION, DAMAGE, OR DEBRIS
LIFT PUMP FLOW
AIR IN FUEL SYSTEM
LEAKING FUEL INJECTORS OR HIGH PRESSURE CONNECTORS
PRESSURE LIMITING VALVE
HIGH PRESSURE FUEL PUMP
INTERMITTENT CONDITION

Back to the grid heater issue. Check and make sure all ground cables are free of corrosion (batteries and fenders), as well as both signal wires on the relay.

banyon

I put on lift pump, fca valve, fuel pressure sensor. No fuel leaks or air in system, no other codes. When I put the lift pump on I cleaned the tank even though it was spotless. New fuel filter. It seems to me it`s the high pressure pump but I hate to put one on until I know for sure that`s the problem. Is there a test I could do? thanks again. Oh, I also checked all grounds.

06RAM2500

Ohm test the injectors. Might have one out of spec (more than 1.0 ohm).