DTC U1170: Loss Of Left Front Power Window Switch Assembly Simple Bus Serial Data: Description

Simple Bus Interface (SBI) provides communications path between all door modules. Left Front Door Module (LFDM) contains both class 2 and SBI circuits allowing it to relay messages between class 2 bus and SBI. Each module connected to SBI is assigned its own recognition code. This code is used to identify which modules are communicating by periodically sending State Of Health (SOH) messages. When ignition switch is in RUN position, each module communicating on SBI sends SOH message every 2 seconds to ensure proper system operation.

DTC U1170 is set when any SBI communications problem between LFDM and LFPWS occurs. DTCs B1982 (battery voltage high), B1983 (battery voltage low), U1300 (class 2 bus shorted to ground), or U1301 (class bus 2 shorted to voltage) must not be current or diagnostic will not run. DTC U1170 is stored in module memory. No driver warning message will be displayed for this DTC. Loss of SBI will cause LFDM to use default values for initialization data.

Under all fault conditions, DTC U1170 will clear automatically when SBI becomes operational again or with each ignition cycle. History DTC will clear after 50 consecutive ignition cycles if condition for malfunction is no longer present. Current and history DTCs can also be cleared using scan tool or On-Board System Diagnostic (OBSD) feature.