S-AFCII Help!

RotaryDiagnostics · 06-20-2009, 02:32 PM

I'd appreciate some assistance from the S-AFC users on the forum. This relates to an S-AFCII installed on an S5 turbo.

Question is: Do I need to rerun setup after momentarily disconnecting the S-AFCII power wire from the ECU?

Background: At the track last weekend I was having a rough running condition at idle and a minor miss at high rpm. The problem was undoubtedly related to A/F ratio since the tailpipes eventually became very sooty black. So troubleshooting the obvious possible culprits like TPS settings, vacuum leaks, plugs revealed nothing out of spec. Then I checked out the S-AFCII harness connections at the ECU for any problems. [It was installed by a previous owner.] In checking the splices, the power wire (red) pulled out of the quick splicer. Fixed that and the other splices checked out OK.

So when restarting the car it would barely run. No rpm readout on the controller and check engine lights for TPS and AFM. As a stopgap I removed the S-AFCII from the loop and it runs OK now, but I want to get the S-AFCII up and running again. All help appreciated.

06-20-2009, 02:32 PM	#1
RotaryDiagnostics Compression Tester Man Join Date: Feb 2009 Location: Mont Alto, PA Posts: 137 Rep Power: 17	S-AFCII Help! I'd appreciate some assistance from the S-AFC users on the forum. This relates to an S-AFCII installed on an S5 turbo. Question is: Do I need to rerun setup after momentarily disconnecting the S-AFCII power wire from the ECU? Background: At the track last weekend I was having a rough running condition at idle and a minor miss at high rpm. The problem was undoubtedly related to A/F ratio since the tailpipes eventually became very sooty black. So troubleshooting the obvious possible culprits like TPS settings, vacuum leaks, plugs revealed nothing out of spec. Then I checked out the S-AFCII harness connections at the ECU for any problems. [It was installed by a previous owner.] In checking the splices, the power wire (red) pulled out of the quick splicer. Fixed that and the other splices checked out OK. So when restarting the car it would barely run. No rpm readout on the controller and check engine lights for TPS and AFM. As a stopgap I removed the S-AFCII from the loop and it runs OK now, but I want to get the S-AFCII up and running again. All help appreciated.