Conditions for Running the DTC
WARNING: This page is about a different car, the 2018 Buick Encore. However, it is still accessible from the selected car via links, so may be relevant.
P121B
- The ECM commands the MAF ON.
- The ECM commands the powertrain relay ON.
- The ignition voltage is at least 11 V.
- The DTC runs continuously when the above conditions are met.
P121C
- The ECM commands the MAF OFF.
- The ECM commands the powertrain relay ON.
- The ignition voltage is at least 11 V.
- The DTC runs continuously when the above conditions are met.