Diagnostic Aids
WARNING: This page is about a different car, the 2019 Chevrolet Malibu. However, it is still accessible from the selected car via links, so may be relevant.
- The ECM is responsible for setting the voltage codes, since the DC/DC converter cannot set DTC's. The ECM monitors the DC/DC Converter voltages via the data line. If the ECM loses communication with the DC/DC Converter for any reason the ECM will not be able to monitor the voltages, therefore the ECM interprets this as a loss of voltage and DTCs P3052 and/or P3056 may set as a result.
- If DTC P3056 is set, verify K20 ECM and T19 Power Supply Transformer grounds are clean and tight.
- Ground circuits for the area of customer concern are clean, tight, and in the correct location.
- Verify all devices powered by the T19 Power Supply Transformer are operating properly.
- B+ circuit terminal 8 supplies voltage to output circuit terminal 9, function 12 V regulated supply voltage 2