Intake air heater relay

[Mark Rinker]

Another part needed for the 2002 that I have sold, and am taking care of a few details for the new owner.

Since the mornings have turned cooler, I am seeing an SES light with P540 code. Tech says it needs a new Intake Air Heater Relay...big bucks through GM.

Anyone know of a source for a good take-off part?

[npauli]

I thought these trucks had glow plugs, not intake heaters. Am I mistaken?

[DmaxMaverick]

Intake heather AND glow plugs. Keep the EPA happy.


The relay should be in the same location as the GP controller. Located above the valve cover, rear of the driver side. The relays are expensive, if purchased separately. You can replace the entire controller assy for about 1/2 the cost of the individual relays. www.gmpartsdirect.com and rockauto.com carry them.

If you get one from a salvage yard, snag the whole GP/heater controller.

[Mark Rinker]

Thanks for the information. No luck with salvage yards, the parts go with the complete engines.

My local GM dealer ordered 'the part' (not sure if they are ordering separate relays, or the complete GP controller) but it hasn't come in.

Do you have a GM part# for the entire assembly?

[DmaxMaverick]

97371491 is the part# I have for the GP relay module (federal), which also controls the IAH. $46 at gmpartsdirect.com. $78 list at the dealer.

[Mark Rinker]

Thanks for the information and part#!