2020-08-26
GCU7 Manual
32
XIV.
FREQUENTLY ASKED QUESTIONS AND TROUBLESHOOTING
Can’t connect to the GCU
If you see a red DISCONNECTED bar in the bottom it means that either USB CAN interface is not plugged
in or you don’t have proper drivers installed. On Windows 7 and newer, drivers are automatically
installed once you plugged in, but it could take up to 5 minutes from the to finish loading. If you have
Windows XP you need to install the drivers from the drivers folder.
If you see an orange CAN INTERFACE CONNECTED, WAITING FOR THE GCU bar in the bottom, it means
that USB CAN interface is successfully detected and that you need to connect the GCU can bus.
Reasons for GCU not responding:
- GCU is not powered properly (L1 needs 12V and M1 needs GND)
- CAN BUS speed is incorrectly set (You can change interface speed in top right corner)
- CAN BUS is not properly terminated. If you’re connecting to the existing CAN BUS line, it’s a good
chance that CAN BUS is already terminated, so you need to remove the jumper from the USB CAN
Interface (See CONNECTING TO THE GCU). If GCU is not connected to an external CAN BUS line, USB
CAN Interface needs to have the jumper inserted! To check if CAN BUS is properly terminated, remove
the USB Interface from the USB port, power off all the devices (that are connected to the CAN BUS) and
measure resistance between CAN+ and CAN-. Existing network should have reading between 50-60
ohms, while no CAN BUS should have 100 ohms (with jumper inserted). Please note that you need to
measure with car turned off and usb interface disconnected from the USB PORT.
I can shift up, but can’t shift down
This is usually caused by TPS being incorrectly set up. GCU will prevent down shift if TPS is too high. How
high it can be is configured by the
Disable shift if TPS
setting in the DOWN tab. Make sure you have TPS
properly setup, correct
TPS type
selected (GENERAL/SENSORS) and calibrated. See GENERAL/SENSORS
for more info.
Blip works when I activate it from the software, but does not work when shifting
First, make sure the blip is enabled (DOWN/
Blip enabled
checked). Blip will not work if RPM is lower
than the number specified in DOWN/
Disable blip if RPM <.
What this does is it prevents the blip to work
in lower rpms. Enter 0 here to enable blip for all rpms or if RPM signal is not working properly. Lastly,
check if DOWN/
Blip until barrel moves (deg)
is 15 or more. What this does is it activaing the blip until
gear position reaches this degrees (relative).
Cutting doesn't seem to work when I shift up
Most common reason for the cut not to fire is when clutch is pressed. Make sure that clutch switch is
working properly (input button must »light on« when you press the clutch. Invert it if needed). If you do
not have clutch switch installed, you need to disable it. Cut will also not work for N->1 and R->N shifts.
