Where Is the Crank Sensor on a 2002 Chevrolet Impala 3.4 Liter Engine Located?by Justin Cupler
The 2002 Chevy Impala with a 3.4-liter engine has two crankshaft position sensors, crankshaft position sensor A and crankshaft position sensor B. Replacing the sensors is easy once you know where they are.
Crankshaft Position Sensor A
Crankshaft position sensor A is the sensor on the part of the engine block facing the front of the vehicle. This sensor is slightly above and toward the passenger's side of the engine oil filter.
Crankshaft Position Sensor B
Crankshaft position sensor B is attached to the block of the engine near the rear of the engine compartment. It is exactly below the exhaust manifold, toward where the transmission and engine bolt together.
The crankshaft position sensor is a magnetic sensor. It measures the exact position that the crankshaft is in and the engine's rpm and relays that information to vehicle's computer. The computer measures the timing of the ignition and fuel injectors according to the crankshaft's position.