Hello all
I recently set code PO540 which I understand is the intake air heater. I have checked Rock Auto and GM parts direct and can't find anything. Any help would be greatly appreciated.
Bill
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Hello all
I recently set code PO540 which I understand is the intake air heater. I have checked Rock Auto and GM parts direct and can't find anything. Any help would be greatly appreciated.
Bill
The GM part # for 2001 is 97251974. I don't have the 2003 part number, but you can compare it, or we'll get it, if necessary. They look the same, to me, and they should be, but that doesn't mean much with these late model engineers.
A more likely suspect, is the relay. It isn't uncommon for them to fail, especially on federal emission trucks (CA emission trucks seem to have fewer problems with the relays for some reason). Wires/connectors can also be suspect.
First, check the heater for resistance. It should be near a dead short to ground, so a test light is usually enough to tell. If it has continuity to ground, it's probably OK.
[normally, the voltage test described below is done first, but you are already looking to buy a new element]
Next, check for voltage at the heater during a cold start. Using a VOM (Volt-Ohm Meter) or a test light, you should have battery voltage at the heater lug within a few seconds, when the key is cycled to "ON", if the following conditions are met: The intake air temp must be below 73°F, engine running; or the coolant temp must be below 121°F with the key ON, engine OFF, for more than 3 seconds, in order for the heater to be energized and monitored by the PCM.