fault code PO480
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fault code PO480
I just got back from a trouble free 900 mile round trip in my 99 C5, 105 degree weather on cruise most of the time at 80 to 85 MPH. The next day after driving the car 5 min. the "check engine' light came on. It was a history code PO480. Fan relay #1 according to the GM manual. I erased it but throughout the day it reoccurred 3 or 4 more times. My question is what's the most likely suspect? Relay, connection or PCM? And where is the PCM/TAC module. I have no source for a scan tool and the trouble tree requires it on a few diagnostics.
Drifting
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From: NW Chicago
St. Jude Donor '12-'13-'14-'15
I just got back from a trouble free 900 mile round trip in my 99 C5, 105 degree weather on cruise most of the time at 80 to 85 MPH. The next day after driving the car 5 min. the "check engine' light came on. It was a history code PO480. Fan relay #1 according to the GM manual. I erased it but throughout the day it reoccurred 3 or 4 more times. My question is what's the most likely suspect? Relay, connection or PCM? And where is the PCM/TAC module. I have no source for a scan tool and the trouble tree requires it on a few diagnostics.
https://www.corvetteforum.com/forums...circuit-b.html
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Thanks for that link. Right now all I can confirm is the passenger side fan is running I think at high speed. The driver side fan is somewhat hidden by the ABS pump. I'll recheck tomorrow with a brighter flash light.
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I verified today that the engine temp fan turned on at high speed at approx. 228 degrees F. The A/C fan is on, I think, on high at any temperature prior to 185 degrees F. The engine temp was stable at 230 degrees ambient at 80 degrees sitting in the driveway 196 or so, driving in town. I need to get this car up on a rack to check for frayed loose wires or rodent damage. (history of rodent damage to vacuum hoses above the PCM)
Last edited by grantorino; Jun 8, 2018 at 01:56 AM.
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It.s FIXED! I was finally able to get the car up on a rack today. I found a large plastic bag tangled up in the smaller engine temp fan blades. Took about 20 minutes to get all the remnants out. On the drive home no codes!
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Well, it's not fixed after all. The fault code returned and I've verified no engine. temp fan operation. Going into the shop next week. It points to a failed fan motor at this point. I will update as soon as it's diagnosed.
Last edited by grantorino; Jun 22, 2018 at 02:44 AM.
