Intake heater coding on startup

Alan McDonough · May 18, 2022

2000 2500, 5.9 Diesel: This one is driving me crazy. It started while driving the truck threw a P0381 code. I found the intake heater relays bad. Replaced the relays and cleared the code. Drove the truck for about two hours to reset the computer so I can pass smog here in California. Parked the truck for the night, went out the next morning turned the key to on and wait as usual. started the truck and within a minute the truck threw the P0381 code again. Threw the meters on the relay coils and amp meters on the heaters and and watched the heaters cycle normally. Went through the hole sequence of reset,driving, parking over night and it happened again twice. It appears it only throws the P0381 code in the morning.
Any ideas. Does the heaters turn on different on a cold start?

maxx442 · May 20, 2022

You may get some responses if you post this in the second gen section or possibly in the Cummins specific section.

RamElectricalRet · Jul 2, 2022

The heaters will not actuate with a hot engine (they're not needed with a hot engine). The amount of time the heaters (two) initially actuate before cranking and then cycle after starting is dependent on the engine temperature.

06 Dodge · Jul 2, 2022

Alan McDonough said:
2000 2500, 5.9 Diesel: This one is driving me crazy. It started while driving the truck threw a P0381 code. I found the intake heater relays bad. Replaced the relays and cleared the code. Drove the truck for about two hours to reset the computer so I can pass smog here in California. Parked the truck for the night, went out the next morning turned the key to on and wait as usual. started the truck and within a minute the truck threw the P0381 code again. Threw the meters on the relay coils and amp meters on the heaters and and watched the heaters cycle normally. Went through the hole sequence of reset,driving, parking over night and it happened again twice. It appears it only throws the P0381 code in the morning.
Any ideas. Does the heaters turn on different on a cold start?

I do recall that the grid heaters normally come on at temp around 60 or lower as for what caused the code can't help you so head over to TDR: https://www.turbodieselregister.com and ask the guys in second gen for advice...

Intake heater coding on startup

Alan McDonough

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maxx442

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RamElectricalRet

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06 Dodge

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