- 1056BA Check injector efficiency
- 1056BF Check efficiency of hot film air flow meter
- 1056BG Check on operation of engine coolant temperature sensor
- 1056BH Check altitude corrector efficiency
- 1056BM Check operation of accelerator pedal potentiometer
- 1056BN Check on operation of throttle casing actuator
- 1056BX MAP/flow meter signal plausibility