VIN:VF3LB9HPAES159012
Looking for engine power supply to fuel regulator solinoid, turbo control valv...
Thanks for the VIN. That confirms it's a 308 T9 with the 1.6 HDi (DV6FD engine).
On this BSM-Z01 architecture (EMP2 platform), you won't find an external "Main Relay" for the engine. It is integrated directly inside that BSM unit you are looking at.
Fuses
F6, F7, and F8 share a common internal power rail inside the BSM. This rail is fed by that integrated Main Engine Relay.
Here is how it works and why those fuses are likely dead:
- Permanent Power: The BSM receives permanent battery power via the large ring terminal stud and sometimes a high-amperage connector.
- Ignition On: When you turn the key, the BSI wakes up and tells the Engine ECU to wake up via CAN bus.
- ECU Command: The Engine ECU checks its safety parameters (immobilizer status, etc.). If everything is okay, the ECU sends a ground (earth) signal via a small wire back to a specific pin on one of the BSM connectors.
- Relay Activation: This ground signal energizes the coil of the relay integrated inside the BSM.
- Power Distribution: The internal relay closes and sends power to the internal rail feeding fuses F6, F7, F8 (and usually others like F4 or F10 depending on the exact variant).
Troubleshooting Steps:
Since all three are dead, the issue is not the fuses themselves, but the supply to them.
1. Check Main BSM Feeds
Before anything else, check the large Maxi-fuses that sit underneath the BSM tray or right next to the battery positive terminal. Make sure the BSM itself has its main heavy-gauge 12V supply.
2. Check the ECU Command Signal
This is the critical test. You need to find out if the ECU is trying to turn the BSM on.
- Locate connector 28V NR (28-pin Black) or sometimes 28V GR (28-pin Grey) on the BSM.
- You are looking for the wire coming from the Engine ECU that controls the main relay. On many T9s, this is often around pin 21 or 22 of the 28-way connector, but it varies.
- Test method: Use a multimeter back-probed into the connector. With ignition ON, you should see near 0V (ground) on the control pin if the ECU is commanding the relay on. If you see 12V (or floating voltage), the ECU is not commanding the relay on.
Summary:
If the ECU is sending the ground signal, but F6/F7/F8 have no power -> The BSM internal relay is faulty (replace BSM).
If the ECU is
not sending the ground signal -> The problem is elsewhere (ECU not waking up, immobilizer issue, or faulty ECU).