DTC U1161: Loss Of Pass Door Module SBI: Description

Simple bus interface (SBI) line is used to communicate information between door modules. Each module connected to SBI is assigned its own recognition code (address). This DTC is used to identify which modules are communicating. Modules communicate with each other by periodically sending State Of Health (SOH) messages.

When ignition switch is in ON position, each module communicating on serial data line sends a SOH message every 2 seconds to ensure that system is operating properly. When left front or Driver Door Module (DDM) stops communicating on SBI data line, such as DDM losing power or ground, SOH message it normally sends on serial data line every 2 seconds disappears. Module which expects to receive SOH message detects its absence and sets an internal DTC U1161 associated with loss of SOH of PDM, which is no longer communicating on SBI data line.

This DTC only sets if DTC U1300 or U1301 is not current in module memory. DTC will set if module does not receive SOH message from PDM in 5 seconds.