In Peugeot vehicles (such as the 207, 308, 408, 3008, Partner, and RCZ), the acts as the main fuse box and power distribution hub located under the hood, next to the engine. It works alongside the BSI (built-in systems interface inside the cabin) to deliver power to vital engine electronics.
A short circuit to the positive battery terminal or a faulty wiring harness. Common Solutions
The ignition positive relay is embedded directly onto the printed circuit board (PCB) inside the unserviceable under-hood BSM engine fuse box. Over time, moisture intrusion can cause corrosion on the internal traces or fuse box pins, forcing a continuous bridge between constant 12V battery power and the ignition output circuit. 2. Wiring Harness Chafing and Short Circuits a9b7 peugeot
"Fault in the ignition positive relay (+APC) or in the output harness from the relay"
A: Expect $120–$180 for diagnostic time. Armed with this article, you can do it yourself for free. In Peugeot vehicles (such as the 207, 308,
If you own any of these vehicles and have a persistent electrical gremlin, scanning for should be your first step.
Disconnect the battery safely. Unplug all the large wiring connectors going into the BSM engine fuse box. Look closely inside the plugs for green or black oxidization. If a pin is broken off or severely corroded, the plug housing or the entire BSM module must be repaired or replaced. Clean the connectors using a high-quality electronic contact cleaner. Step 3: Verify Power Outputs Common Solutions The ignition positive relay is embedded
: The internal relay has failed. Because the BSI houses the immobilizer chip information, replacing it requires a specialized cloning process or a brand-new module configured via a Peugeot Diagbox tool.