...and apparently my check engine light is burned out (more likely unscrewed by the guy who sold me the car). But my radiator fans work! I seen 'em!. What is going on here??? TIA!

Perhaps there was a cooling fan problem, it set the code, the previous owner fixed the problem but didn't clear the code? Does the code keep coming back?

Also, when you observed the fans coming on, did they do it all by themselves or was the A/C or defrost mode on ? (those functions force both fans on regardless of coolant temperature.)

...and apparently my check engine light is burned out (more likely unscrewed by the guy who sold me the car). But my radiator fans work! I seen 'em!. What is going on here??? TIA!

The P1502 code typically indicates the ECU senses that the engine is running too warm, and when it commands the fans to run that doesn't correct what it's sensing.

 

Assuming there are no other codes, first check the simple stuff. With the engine cold, make sure the radiator is filled (don't just check the level in the reservoir tank). Verify that air flow through the radiator (or A/C condenser) isn't partially blocked with dead insects, etc.

 

As already asked, have you seen both fans come on with the engine hot (but the A/C not on)?

 

One possibility is that the engine coolant temperature sensor (ECTS) is beginning to fail.

thanks for all the great ideas. I think my first step should be to get my check engine light working. Question: does the check engine light normally cycle on when you turn the key to ON? If so, then my light is definitely burned out.

Yes, all indicator lights on the dash should cycle when you first turn the key on. This verifies that all bulbs are in place and working correctly.

OK guys, you're going to love this one.

 

The check engine light and holder was missing! I didn't have a spare holder, so I borrowed the 'FWD' holder and bulb. Now my check engine light works and I am currently trying to make it go on again by idling the engine at 1500. Also trying to get the fans on. So far only the driver's fan will spin. Do they ever run independently?

 

If the check engine light is off right now (I disconnected the battery to pull the instrument cluster) does this mean I have no code that the smog tech could find? History codes clear, right? Cheers.

Edited April 23, 201015 yr by sean56a
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There is something called "readyness status" which you would fail on if you took your car to be tested now. Basically, the computer runs a series of self checks of each system and once it has verified that each system is working properly it flags that system as tested in its memory. In order for these checks to run, you have to drive the car a while at different speeds, multiple start-stop cycles etc.

 

If whatever set your fan code is an intermittent problem it's quite possible you can drive the car long enough to set all the readyness monitors to "good" without tripping the check engine light. I'd say that if you can drive it for a couple of days under different road conditions and the CEL doesn't come on, take it to be inspected and see what happens!

i remember something about "both fans running all the time" when the diagnostic plugs are connected. but this would only show that they both work. not what it takes to get them to come on. do not leave the diagnostic plugs connected.

 

one of the fans is supposed to come on when the ac is turned on.