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CANTCU isn't detected in the PC software
CANTCU needs +12V and GND to work properly.
- Check that +12V and GND are present at the CANTCU connector (Pins A1 & A8)
- Make sure your PC meets the minimum requirements -> Windows 10/11 operating system
CANTCU PC connection shows green but no information/serial numbers/connection
USB connection not correctly initialized or CANTCU not in normal operating mode.
- Cycle power to CANTCU fully
Firmware update failed resulting in no PC USB connection
CANTCU stuck in bootloader mode.
- Cycle power to CANTCU fully
Problem communicating with server
To protect against malicious intent, the amount of sessions is limited on a per-user basis. Using the flasher normally as intended, for flashing, you will NOT run into this problem. Spamming connections every 5 minutes trying to diagnose a "Transmission not detected" (see below) might block you out.
- Try again one hour later.
Transmission not detected
This indicates that no transmission is found communicating correctly on CAN1 (transmission software information cannot be read). The reasons could be faulty wiring, unsupported transmission, or a 3rd party device/interface wired on CAN1 interfering with communication.
- Check wiring
- Verify that your transmission is supported
- Make sure nothing else than CANTCU and transmission is wired on CAN1
NOTE! If you have a 1stGen 8HP BMW transmission and are able to read adaptations but otherwise not detected, your transmission probably is from an E-Series car and needs an initial bench flash to be suitable for CANTCU-usage.
Flash failed
- As the PC program suggests, try again.
- Make sure you don't have anything else than CANTCU and the transmission wired to CAN1. Anything connected to CAN1 OBD will interfere with flashing!
- If flashing fails continously, contact support via email and attach logs from the failed flashes.
Transmission indicator goes red 30 seconds after powerup
CANTCU controls the transmission wakeup through the WUP-line (and/or CAN-communication). This is done based on the detection of "Ignition On" which is read from the ECU. If you have no ECU communication (red ECU indicator), "Ignition On" will stay at zero/inactive and cause CANTCU to put the transmission to sleep.
- Make sure the ECU indicator is green ( = you have an ECU connected)
NOTE! This does not effect flashing of the transmission. When CANTCU Flasher is used, the transmission is always kept on by CANTCU regardless of an ECU connected or not.
OEM shifter goes crazy when trying to put in S/M
This can happen when the shifter is physically wired to CAN1+2, but a CAN3 shifter is selected in CANTCU Configuration, causing two shifters to be present on the CAN-bus simultaneously.
- Select correct shifter in configuration based on how your shifter is physically wired (OEM CAN1+2)
Cannot engage gear
There are certain prerequisites for engaging gears. Check the following:
- Transmission Immobilizer unlocked (8HPs/DCT F-Series)
- Correct shifter selected
- Engine running
- All running values showing up normally in CANTCU (Engine RPM etc)
- Brake pressed
- Enough oil in the transmission
OEM shifter goes crazy when trying to put in S/M
This can happen when the shifter is physically wired to CAN1+2, but a CAN3 shifter is selected in CANTCU Configuration, causing two shifters to be present on the CAN-bus simultaneously.
- Select correct shifter in configuration based on how your shifter is physically wired (OEM CAN1+2)
Transmission fault present in the car - CAS fault codes
CAS not properly coded and/or PLOCK grounding missing.
- Code CAS properly
- Make sure you have the "PLOCK loop" installed (PnP harnesses) or that you've grounded the necessary CAS pin
BMW E6/7/8/9x wiki instructions
Transmission fault when shifting into 8th gear
The clusters in these cars do not support showing 8th gear
- Select the correct E6x cluster in CANTCU configuration, limiting the highest shown gear to 7th
The cluster has outdated software but can be updated to show 8th gear properly.
- Use BMW Tools (WinKFP) to update the cluster software
Shifts aren't smooth
If swapped from a manual car, DME/DDE might not have torque intervention requests active. Verify by looking at "Target Torque" and "Engine Torque" in CANTCU. While shifting, "Engine Torque" should follow "Target Torque" closely. If not, follow remedies below:
- On most DMEs, a reset of variants is enough
- On DDEs, a software flash normally is required
Transmission is slipping under load
Torque indication from DME/DDE might be inaccurate. This is common on tuned engines (cheated Nm2IQ/load/duration maps etc) due to poor tuning or limitations in the DME. Verify by looking at "Engine Torque" in CANTCU, and compare to real engine output.
- If possible, correct the torque tables in the DME/DDE software.
- Use "Torque Correction Factor" in CANTCU tuning to compensate
NOTE that the transmission also might just be mechanically worn out/broken. Increasing the indicated torque will not fix a mechanical issue.