DTC U1153: Loss Of Serial Communications - CCP: Description

Class 2 serial data circuit is used to communicate information between systems. Each system on the serial data line is assigned its own recognition code, which is used to identify which system is communicating. Systems send a State of Health (SOH) message every 5 seconds to other systems. If those systems fail to send an SOH message back, a corresponding DTC will be set.

DTC U1153 will set when IPC has sent an SOH message to Climate Control Panel (CCP), and no SOH message response was sent back for 3 consecutive monitoring cycles. DTC U1153 will clear when CCP transmits a SOH message to IPC.