: Typically registered as a short circuit to positive .
First, let’s decode the jargon. In the Peugeot Citroën (PSA) diagnostic ecosystem, codes that begin with an alphanumeric sequence like "A9B7" are not standard OBD-II powertrain codes (like P0171). Instead, they are . a9b7 peugeot
While the code is stored in the BSI, the physical relay responsible for "ignition positive" is often housed inside the (Engine Fuse Box). : Typically registered as a short circuit to positive
In the automotive world, specific part numbers often become legendary not for their performance, but for their propensity to fail. For owners of the Peugeot 407 (and the flagship 607), the part number is synonymous with one of the most frustrating electronic failures in modern Peugeot history. Instead, they are
Result: This resolves the A9B7 code in about 30% of intermittent cases.
If all else fails, the BSI itself is damaged (often water ingress). A new BSI from Peugeot costs ~$600. It must be (cleared of its VIN) and then programmed to your car. This is not a DIY job unless you have advanced CAN tools.