B3021 Engine Code Repair

Meaning of B3021 engine trouble code is a kind of body trouble code and theoretically you can drive for a few weeks or even months with a broken MAF sensor. You will notice a decrease in gas mileage and over time the car will eventually start stalling a lot. At a shop, the replacement cost is between $240-$400 depending on the car, but that's usually the cost of parts because the labor is relatively simple.

B3021 Fault Symptoms :

B3021 Possible Solution:

Air Conditioning Pressure Sensor (ACP) Insufficient Pressure Change Each time the A/C clutch engages, the PCM is looking for a pressure change in the refrigerant. If the change in pressure is outside of the calibration the DTC will set. A/C system mechanical failure Open ACP or VREF circuit A/C sensor damaged A/C system electrical failure A/C clutch always engaged Verify A/C system function, including refrigerant charge.

B3021 Code Meaning :

Regarding the B3021 code, it would probably be worthwhile to carefully inspect the wire harness near the intake manifold bracket. This is done most easily from below the car in the area near the oil filter.

B3021 code on vehicles with electronically controlled automatic transmissions, the 3-4 shift solenoid is responsible for actuating the hydraulic circuits to activate clutches or bands that change gears inside the automatic transmission.