ENGINE SYSTEM SERVICE REQUIRED (Diagnostic Report Attached)

[Mitragorz]

2007 S60

SCANNER REPORT:
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2025-08-10_11-21-36.pdf

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A little background. I was replacing the starter on my S60 and I hadn't disconnected the battery. The ratchet touched something, gave off a small spark, and I had that "oh crap" moment. Disconnected the battery and carried on.

First time driving the car, I get an ENGINE SYSTEM SERVICE REQUIRED message. I brought it to my mechanic, he scanned it, and found the radiator cooling fan fault in the ECM. He couldn't command it on with his scanner. I bought a new fan assembly, put it in, and the fan works fine. I also bought my own Autel scanner so I can do this stuff on my own. I can run the new fan with the scanner, and CANNOT run the old fan, confirming I must have shorted out the old unit when I sparked the ratchet.

I reset all the codes, took it for a drive, and no more message. This morning the ESSR message popped back up, I re-scanned it, and the only faults are with the ECM:

DTC 650B FC (Engine Cooling Fan) - Signal Missing Intermittent Fault
DTC6200 Engine Cooling Fan Control Module - Faulty Signal

This is the fan assembly I purchased. The control module is the box on the assembly, correct? It's not located somewhere else on the car, is it?

Additionally, when I do turn the fan on with the scanner, it runs for maybe 10 seconds then spools down all by itself. I'm not sure if that's a normal function or if the signal is getting interuppted, and that's what's causing the above codes... See video (Warning, it may be loud):

Thoughts? Should I try another fan assembly, or could it be something else?

[jonesg]

do more testing, turn the AC on and see if the fan runs longer than a few seconds.

The violet wire is the fan control wire, it passes through the power distribution box near the brake reservoir.
It should be a good place to probe the wire for signal.

The starter wire passes close by, maybe in the same loom, try poking around to see if they're adjacent.
Its possible the major power that got fed into the starter wire burned the loom.

An alternative test is cut the violet wire beneath the ECM and solder/install a jumper wire. Might want an inline fuse.
It passes below the passenger side headlight.

I had a similar problem, I cut the violet wire near the ecm and put a signal in the wire, traced the signal with a fox and hound, found the violet wire had a break near the fan plug.

[cn90]

Try d/c battery ground cable for 10 min.
Then reconnect and see what happens...