What does it mean?
P1146 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Air mass meter -G70 supply voltage .
Symptoms
- Malfunction indicator lamp on with a marked loss of power
- Hesitation, jerking and poor throttle response, sometimes with limp mode
- Rough idle, stalling at low speed or after coming to a stop
- Black smoke and a noticeable rise in fuel consumption
- Hard starting or the engine running better with the sensor unplugged
Likely causes
- Blown fuse or an interrupted supply circuit feeding the sensor
- Corroded, loose or backed-out terminal in the MAF connector
- Chafed supply wire shorting to ground or to an adjacent circuit
- Poor ground connection for the sensor, raising the reference the module measures against
- Internal short inside the MAF sensor pulling the supply line down
- Weak battery or an undercharging alternator leaving system voltage low
- Corroded or loose main ground strap between engine and body
How to fix it
- Check charging voltage and battery condition before testing the sensor itself
- Measure supply voltage at the MAF connector with the key on and again with the engine running
- Check the relevant fuse and confirm the supply circuit is intact back to its source
- Measure ground side voltage drop at the sensor connector while the engine runs
- Inspect the connector for corrosion, damaged locking tabs and pushed-back terminals
- Compare the MAF airflow value against the expected figure for engine size at idle and at raised speed
- Repair the wiring fault where found; replace the sensor only if it is shorting its own supply, then clear codes and road test