With Coolant Control Valve

DTC U0320:00 DETECTION CONDITION AND POSSIBLE CAUSE

DTC U0320:00	EPS control module error
DETECTION CONDITION	When any of the following conditions is met: CAN communication line malfunction between EPS control module and PCM EPS control module internal malfunction Diagnostic support note This is a continuous monitor (other). The check engine light does not illuminate. FREEZE FRAME DATA is not available. Snapshot data is available. DTC is stored in the PCM memory.
FAIL-SAFE FUNCTION	Not applicable
POSSIBLE CAUSE	CAN drive error (EPS control module or PCM) CAN communication line malfunction between EPS control module and PCM EPS control module terminal 1G-Body control module (BCM) terminal 2D EPS control module terminal 1H-Body control module (BCM) terminal 2C Body control module (BCM) terminal 3C-PCM terminal 2S Body control module (BCM) terminal 3D-PCM terminal 2T EPS control module connector or terminals malfunction PCM connector or terminals malfunction EPS control module malfunction PCM malfunction
Courtesy of MAZDA MOTORS CORP.