DTC U1016: Loss Of Communication With Pcm: Notes

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 periodically send a State of Health (SOH) message to other systems. If those systems fail to send an SOH message back, a corresponding DTC will be set. Also, any system that cannot communicate properly will set the corresponding DTC.

DTC U1016 will set when BCM has sent an SOH message to PCM, and no SOH message response was sent back for 5 seconds. PCM will not allow fuel enable processing to occur, which may cause vehicle to display a "engine cranks, but does not run" condition. No driver warning message will be displayed.

DTC U1016 requires an ignition cycle to change from current to history. If conditions for malfunction no longer exist, history DTC will clear after 50 consecutive ignition cycles. DTC U1016 will also clear when conditions no longer exist, or when IPC or scan tool is used to clear codes.