DTC P0542; Intake air heater "A" circuit high.

[JFK]

Would appreciate any info on this code., mainly, how serious it is. The "Haynes Repair Manual" tells me zilch. I'm currently 900 miles from my home and towing our 30 ft. travel trailer. Am I going to have serious problems if I continue to drive? So far, everything is O.K. My ride is a 2015, 6.7L, 4 x 4, auto trans.
Thanks ever so much.
Jim

 

[Ltngdrvr]

That code indicates the intake grid heater is pulling too many amps.
Grid heater has been problematic on some engines, if you do a search for "Grid Heater" I'm sure you'll find many threads on it.
I would first check the power cable from the solenoid to the heater connection and see if there is any corrosion on the connections,, if there is then clean them and clear the code and see if it comes back.
If not, it could be a faulty grid heater.
If you are in extreme cold, it could make the engine harder to start, but won't affect how the engine runs once started.

 

[nukegm]

comrade - i only use my grid heater when its 15 degrees or below...truck starts just fine without it. hopefully the weather wherever you are is warmer than that. cheers! and best of luck.

 

[Cummins12V98]

You have zero control over it coming on. It does what it does even if you instantly start it.

 

[nukegm]

You have zero control over it coming on. It does what it does even if you instantly start it.

comrade - i do have control of its first long draw on the batteries with the " preheat " light .... i agree with you when the engine starts, as it will cycle on its own. cheers sir!

 

[Ltngdrvr]

comrade - i do have control of its first long draw on the batteries with the " preheat " light .... i agree with you when the engine starts, as it will cycle on its own. cheers sir!

Grid heater still is turning on when you turn the key on, no matter if you wait for the preheat light to stay on or not. Grid heater stays on even after the truck starts, until the ecm senses enough intake heat then shuts it off. You have no control over this process.

 

[nukegm]

Grid heater still is turning on when you turn the key on, no matter if you wait for the preheat light to stay on or not. Grid heater stays on even after the truck starts, until the ecm senses enough intake heat then shuts it off. You have no control over this process.

yes sir, i know. thats what i said in above post. the only thing i can control is the 10 20 30 seconds of a long 150 amp plus draw on my batteries while the light is on before the engine starts. if i start the engine immediately i can avoid this immediate long draw/drain. yes, i understand the heater does its " thing " when engine starts. this is indicated by the headlamp dimming etc. cheers!

 

[EDankievitch]

I would unplug the grid heater relay. Last thing you need is the heater bolt arching and burning the head off which will get ingested into the engine. Get home then pull the intake an replace the grid.

 

[AH64ID]

Grid heater still is turning on when you turn the key on, no matter if you wait for the preheat light to stay on or not. Grid heater stays on even after the truck starts, until the ecm senses enough intake heat then shuts it off. You have no control over this process.

There a pre-heat cycle and a post-heat cycle. You can most certainly bypass the pre-heat cycle.

 

[Ozymandias]

No grid heater while starter motor is energized. Only before and after.

From what I experienced....

 

[Hoefler]

Back to the issue at hand, I would suspect you have a battery going south. Have them tested

 

[JFK]

That code indicates the intake grid heater is pulling too many amps.
Grid heater has been problematic on some engines, if you do a search for "Grid Heater" I'm sure you'll find many threads on it.
I would first check the power cable from the solenoid to the heater connection and see if there is any corrosion on the connections,, if there is then clean them and clear the code and see if it comes back.
If not, it could be a faulty grid heater.
If you are in extreme cold, it could make the engine harder to start, but won't affect how the engine runs once started.

Ltngdrvr, a bit more info on my plight, physical location & ambient air temp. Currently we're is southern Nevada (Las Vegas area) where temps are in the 60's to 70's. The "check eng. light came on while I was driving, had been on the road for 'bout an hour. At that point in time I had no way of "reading" the code and just parked the truck (at our camp spot). Several days later we used the truck and the "ck. eng. light" was gone! and stayed gone for several more travels. Then it came back and so far has stayed on. Point being, I can't imagine the heater cycling in these temps AFTER the engine had been started & run for a couple of hours.
And THANKS for your input.
Jim

 

[AH64ID]

IIRC the grids will cycle when the intake temp is less than 66°F.

I agree it’s probably best to disconnect the relay until you can diagnose. A stuck open relay would not be good.

 

[MtnRider]

I sure hope it's not you grid heater bolt failing, that could be catastrophic to the engine and has happened more then I would like to see on these trucks.
Check the cable connection at the grid heater and see if you can wiggle it. If you can I would not start it until you can take it apart and inspect it. If it fails it will swallow the bolt on the inside of the manifold and be very costly.

.

 

[Ltngdrvr]

Ltngdrvr, a bit more info on my plight, physical location & ambient air temp. Currently we're is southern Nevada (Las Vegas area) where temps are in the 60's to 70's. The "check eng. light came on while I was driving, had been on the road for 'bout an hour. At that point in time I had no way of "reading" the code and just parked the truck (at our camp spot). Several days later we used the truck and the "ck. eng. light" was gone! and stayed gone for several more travels. Then it came back and so far has stayed on. Point being, I can't imagine the heater cycling in these temps AFTER the engine had been started & run for a couple of hours.
And THANKS for your input.
Jim

Yeah, you can disconnect the cable from the solenoid. The truck will start even if it does get pretty cold.
Then get it diagnosed/repaired when you can.

 

[Joseph Donnelly]

Check the heater grid nut near the air intake horn to make sure it is tight.

 

[JFK]

Yeah, you can disconnect the cable from the solenoid. The truck will start even if it does get pretty cold.
Then get it diagnosed/repaired when you can.

Well, my story JUST keeps getting better & better. After reading your suggestion, I consulted my "Haynes" for info on the "solenoid" & where it's located. According to Haynes, thee are 2 relays located on the "right battery" (they even showed a photo), not a solenoid. After closer inspection, I found zero relays, but I did see something that MIGHT be a solenoid located adjacent to the "right battery". But it's not the type (physical size & type of housing) that I've worked with in the past. So I'm not sure if what I call "the solenoid" is in fact that. It's got 4 wires attached; 1 each 6 gauge battery ( + & -); 1 each non-color coded coming out of a wiring harness. The 2 battery wires are "bolted" on, the 2 blk's are a push/pull fit (picture a spark plug wire). So it fits the description of a solenoid........but is it the heater grid solenoid?

 

[EDankievitch]

Sure sounds like it. Remove the black push on terminal that should disable the grid heater.

 

[Ltngdrvr]

Well, my story JUST keeps getting better & better. After reading your suggestion, I consulted my "Haynes" for info on the "solenoid" & where it's located. According to Haynes, thee are 2 relays located on the "right battery" (they even showed a photo), not a solenoid. After closer inspection, I found zero relays, but I did see something that MIGHT be a solenoid located adjacent to the "right battery". But it's not the type (physical size & type of housing) that I've worked with in the past. So I'm not sure if what I call "the solenoid" is in fact that. It's got 4 wires attached; 1 each 6 gauge battery ( + & -); 1 each non-color coded coming out of a wiring harness. The 2 battery wires are "bolted" on, the 2 blk's are a push/pull fit (picture a spark plug wire). So it fits the description of a solenoid........but is it the heater grid solenoid?

My truck is still covered in snow or I'd go take a pic and post it.
I'm sure someone else on here has a pic or could take and post one for you.
Here is a pic of the solenoid by itself...
#ad

 

[gsbrockman]

@JFK
It is the grid heater solenoid. I just replaced mine about two weekends ago. My part number was 5187880AC.