It may be difficult to diagnose a vehicle that has components you aren’t familiar with. This Tech Tip will show you the ropes by guiding you through a diagnosis on the Prius. Hopefully your repair is as simple as this Real Fix and the loose DC/DC connector is the only issue.
Vehicle
2010 Toyota Prius Base, 1.8L
Complaint
The customer states the check hybrid system light is on.
Cause
Connected a scan tool and retrieved diagnostic trouble codes: P0A0D – High Voltage System Inter-Lock Circuit High; P0A09 – DC/DC Converter Status Circuit Low Input and U110 – Lost Communication With Driver Control Module. Cleared codes, performed a road test and found the codes returned. Performed a road test while monitoring live scan tool data and observed the DC/DC converter parameter was erratic. Put the vehicle into service mode by removing the hybrid system service plug, performed a visual inspection of the DC/DC converter wiring harness and connector and detected no obvious faults. With the ignition on and the engine off, used a multi-meter to check for the presence of voltage and ground at the DC/DC converter connector and found ground was not present at all times. Disconnected the DC/DC converter connector and found the connector was not fully seated when disconnecting the DC/DC connector.
Correction
Resecured the connector, cleared codes and verified the vehicle operated properly. The customer’s concern did not return.
Courtesy of Mitchell1 SureTrack Real Fix
