Chip-Tools

ITDEENBGES

Bench and BSL connections for Bosch MED17.7.x / MED17.8.x / MEVD17.2.x (Mercedes, BMW, Mini, Jaguar, Land Rover, Infiniti)

Bench connection diagrams for reading and writing the Bosch MED17.7.x, MED17.8.x and MEVD17.2.x ECUs with the ECU Programming Tool. The manual separates two types of wiring: the bench CAN connection for reading the password in boot mode, and the actual "BSL connection", which on some variants is the only way to read the microcontroller.

Procedure

1. Identify precisely the Bosch designation printed on the ECU label (for example MED17.7.2, MED17.7.3.1, MED17.7.5, MED17.7.8, MED17.8.3, MED17.8.31, MEVD17.2.3 ... MEVD17.2.P) and the microcontroller (TC1793 or TC1797): every variant has its own dedicated diagram in the manual.
2. Open the ECU and set it on an insulating, antistatic surface with the board accessible from both sides: the BSL points and the CAN points to hook onto are found on the connector pins and on the board's test points.
3. Bring bench power to the ECU (12V+ and GND) following the diagram on the page for your variant, and check current draw before connecting any data line.
4. For password reading in boot mode, connect the two CAN lines as specified for your variant: on the MED17.8.3 TC1797, CAN HIGH (red) on pin 60 and CAN LOW (blue) on pin 61; on the MEVD17.2.3 TC1793, CAN HIGH (red) on pin 28 and CAN LOW (blue) on pin 13.
5. Where the manual also gives a "BSL connection" entry (MED17.7.2 TC1797, MED17.8.3 TC1797, MEVD17.2.4 TC1797, MEVD17.2.G TC1797), additionally make the BSL jumper shown in the photo on that page: without that point the microcontroller will not enter boot mode.
6. Connect the AVDI to the wired-up set, start the ECU Programming Tool and select the matching ECU; do a full read (backup) first and only then any writing.
7. If the password read fails, before redoing the loom check you have not swapped red and blue: it is the most frequent mistake, because the CAN pins change between MEVD17.2.x variants even though the connectors look identical.

Reference screenshots