P2609 Intake Air Heater System Performance

Heater went on for the first time in few months when I went to start the truck this morning. Check engine light blinks at me and whatcha know I got a code.

So any ideas what the issue might be? Truck has 29308 miles on it so I still have a warranty but I'd like to have an idea whats up before it goes back to the dealer.

Thanks

 

Before I take it to the dealer I'd check the connection on the grid heater. If you have a code reader, after checking the connection, clear the code on the code reader. If there is still a problem it will pop the code again. Then I would take the truck to the dealer. I try to limit the dealer touching my truck as much as possible...

 

Good idea, don't have a code reader though. If the connection was loose and I fix the problem will the code still be in the computer or does it need to be cleared?

Where would the connection for the heater be located?

 

P2609 actually means no voltage drop seen at grid heaters. Had the same code pop up when I forgot to hook the cable up and it shorted against the block. So, it's either the cable shorting out on the block (look at the clamps that secure it to the block), or a burnt up/shorted grid heater. If it's shorted can be repaired, burnt up, needs to be replaced. Also could be a faulty relay.

 

1. INTAKE AIR HEATER OPEN
Measure the resistance between the intake air heater supply and ground terminal on each intake air heater.
Is the resistance less than 10 Ohms?
Yes >> Go To 2
No >> Replace the open Intake Air Heater.




2. INTAKE AIR HEATER GROUND OPEN
Measure the resistance of the intake air heater ground circuit between the intake air heater terminal and the intake
manifold cover ground connection.
NOTE: The intake air heater circuit is grounded through a conductive gasket on the top and bottom of the
air heater (grey colored gaskets).
Is the resistance less than 10 Ohms?
Yes >> Go To 3
No >> Repair the open Intake Air heater ground or replace both heater gaskets with the proper conductive
gaskets

 

3. OPEN BATTERY CABLE FROM INTAKE AIR HEATER RELAY
Measure the resistance of the battery cable between the intake air heater and the intake air heater relay for both
intake air heaters.
Is the resistance less than 10 Ohms?
Yes >> Go To 4
No >> Repair The open or high resistance battery cable from the intake heater relay to heater.


4. BATTERY CABLE OPEN
Measure the resistance of the battery cable between the battery and the intake air heater relay for both relays.
Is the resistance less than 10 Ohms?
Yes >> Go To 5
No >> Replace the battery cable from the battery to the Intake Air Heater Relay


Some simple things you can check before you head out.

 

slightly off topic, but if its broken, how bad is that? I see some guys sigs claiming to have a grid heater delete on it. some people even say they dont even pay attention to the WTS light. obviously a truck that new, and under warranty, it doesnt hurt to have it replaced. I was just curious about the whole thing.

 

Most of those guys live in a year round warm climate so they don't need the grid heaters.....

 

ahh, thats true.

 

So heres an update on the P2609 code my truck threw 3 weeks ago. It came back, this is the 4th time.

1st time to dealer, they reflashed the puter

2nd time back, the repalced grid heater and all gaskets

3rd time back, they reflashed the puter...again....

Goes in on Wednesday to have it checked over again. Kinda curious what the "fix" for the 4th trip will be.

Thanks to 06Ram2500 for the great leads into potential problems, but I think this one is over my head and definitely got the best of the dealer so far.
Anyone know of a dealer with a good diesel tech located in the Jersey shore area? These guys get one more crack at it and then I find someone else.

 

I know it's a warranty thing so it should be fixed but I agree also with unhooking it. Even in cold weather how much good is the grid heater really doing? Seems to me that there is more volume than that little heater can effectively heat. I mean you wait for it to kick off before you start the truck,right? As soon as it kicks off it starts to cool off. As soon as you crank the engine it starts sucking huge amounts of cold air through the heater further cooling it off. I know it cycles a few times after start up but IMO it does little to help cold starts. To me it's kinda like heating a stadium with a hair dryer,not real effective.

 

I think you'd be surprised how much difference it makes in really cold temps. Ever notice right after start-up when they are cycling how much the lights dim, how much the amp guage drops, and how much the engine is placed under load? Take that into consideration combined with the fact that our trucks run dual batteries, a huge alternator, and such a powerful engine to turn that alternator. Considering we're talking that much draw using DC voltage I would imagine those things probably kick out an impressive amount of heat. Think about how much load an AC compressor places on the motor of a typical gas car. I don't ever notice the AC compressor on my truck but I sure do notice the grid heaters. Besides, at idle there really isn't THAT much air being pulled into the engine. That's just my perception... I know in extreme cold that even WITH the heaters my truck is an angry cuss for the first minute or so...