2014 Chevy Cruze (Diesel) Radiator Fan Always On | The Car Community | Page 1

cobalt siren Jul 28, 2024, 2:02 PM

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Helped a friend replace their radiator fan, which had stopped working (tested outside the vehicle standalone, it’s definitely dead). Now, the brand new one is on whenever the battery to the vehicle is plugged in.

Tested all cooling fan relays and fuses, all working. Pulled codes, P0691 is the only one coming up. Have a temp sensor for the radiator lined up next for repair.

Any ideas what it could be? New fan remains on high, regardless of settings and wouldn’t turn off so we unplugged battery for now. Maybe a short somewhere but at this point I’m lost.

opaque rivet Jul 28, 2024, 2:17 PM

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It’s actually possible the temp sensor is indicating the coolant is hotter than it is, and the car is constantly running the fans as a result in an attempt to cool it down. Do you have a way to read live data and, if needed, a multimeter?

cobalt siren Jul 28, 2024, 9:22 PM

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I’ve got a multimeter, an obd scanner, and a cable to run from the car to a laptop for more specific temp readings. Assuming the thermostat is bad, should that jump out on me on the readings?

opaque rivet Jul 28, 2024, 9:43 PM

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Yep. If it’s reading over 200 and you just started the car, that’s going to be a problem

cobalt siren Jul 29, 2024, 2:25 PM

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Will check as soon as I’m home today - thanks for the recommendation.

cobalt siren Jul 29, 2024, 7:19 PM

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Unfortunately, reading 37C at startup so guess it knows the radiator isn’t hot.

opaque rivet Jul 29, 2024, 7:20 PM

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Copy. Few moments let me see what I see

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Doco says the P0691 can be a cause for cooling fan always on, so we will focus our efforts there

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Ground fault on the cooling fan control module b+ supply circuit is a cause for p0691

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Four wires on your connector to the fan motor: black, white/blue, grey, yellow. Black is ground, you want to disconnect the fan motor and then with ignition on engine off, put a test light between that pin on the connector (for the black wire) and a ground. Let’s see if it lights up.

cobalt siren Jul 29, 2024, 10:07 PM

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Let me see if I can dig up a connector now that I’m off work

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No test light, do have a multimeter. Assuming I can just set it to resistance to check ground fault

worn harnessBOT Jul 29, 2024, 10:21 PM

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GG @cobalt siren, you just advanced to level 2! Chat more to level up and earn top roles!

opaque rivet Jul 29, 2024, 10:21 PM

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Bingo

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And I left work so I don’t have the doco handy, so tomorrow I’ll post the instructions I’ve got. It’s a troubleshooting tree so it’s pretty absurd to try and follow

cobalt siren Jul 29, 2024, 10:23 PM

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All good, sorry for the sporadic responses as I’m going back/forth between work and the car. My regular 9-5 isn’t wfh so I’m not with the car during the day unless I intentionally head home

#2014 Chevy Cruze (Diesel) Radiator Fan Always On