Renesas RH850 – “Target connection failed” error when trying to connect

[Pawel26]

Hi,
I’m trying to connect to an Airbag SRS module based on a Renesas RH850 microcontroller and I’m facing the following error:

Target connection failed”
The connection is made directly to the PCB via test points / pins according to the pinout (JTAG / debug interface).
Issue:

• The programmer correctly detects the interface
• There is no communication with the MCU
• The software shows only the message
  “Target connection failed”

Configuration:

• MCU: Renesas RH850
• Module: Airbag SRS (VAG)
• Connection method: direct PCB connection (test points / pins)

Questions:

1. Can the “Target connection failed” error indicate:
   • a locked MCU
   • debug protection enabled
   • an issue with the connection or initialization sequence?
2. Does the RH850 require a specific reset / boot / debug sequence to allow connection?
3. Is it possible that the pinout is correct, but the MCU still refuses communication?
4. Has anyone experienced similar behavior with RH850-based airbag modules?

I’ve attached photos of the wiring and setup.
Any help or guidance would be appreciated