FORD LDM Localization

The Network shall meet the requirements as defined per the following failure modes:
• LDM Power Loss – LDM shall not interfere with normal communication among the remaining bus ECUs (LDM, HCM) during a loss of power (or low voltage) condition. Upon return to normal power, normal operation shall resume without any operator intervention within a time determined by the function latencies chapter.

• Bus Wiring Short to Ground – Network data communications may be interrupted but there shall be no damage to any ECU when the bus is shorted to ground. A network impedance of less than 50 Ω between the bus and ground shall be considered a short to ground and continued communications are not guaranteed or required. Upon removal of the fault, normal operation shall resume without any operator intervention within a time determined by the function latencies chapter.

• Bus Wiring Short to Battery – Network data communications may be interrupted but there shall be no damage to any device when the bus is shorted to positive battery less than 26.5 V (Vbatt < 26.5 V). A network impedance of less than 50 Ω between the bus and battery shall be considered a short and continued communications are not guaranteed or required. Upon removal of the fault, normal operation shall resume without any operator intervention within a time determined by function latencies chapter.

• A short or open in any single wiring circuit of an ECU, except for power, ground, or serial data, shall not preclude the ability to communicate with that ECU for diagnostic purposes.

Note: Diagnostic purposes is only valid for report/status frame.