Acura TSX / Honda Accord CL. Manual — part 561

energized, and enriches the mixture to assure smooth transition to the A/C mode.

AIR FUEL RATIO (A/F) SENSOR

The A/F Sensor operates over a wide air/fuel range. The A/F Sensor is installed upstream of the TWC, and
sends signals to the ECM/PCM which varies the duration of fuel injection accordingly.

Fig. 34: Identifying Air Fuel Ratio (A/F) Sensor

BAROMETRIC PRESSURE (BARO) SENSOR

The BARO sensor is inside the ECM/PCM. It converts atmospheric pressure into a voltage signal that modifies
the basic duration of the fuel injection discharge.

CAMSHAFT POSITION (CMP) SENSOR B

CMP sensor B detects the position of the No. 1 cylinder as a reference for sequential fuel injection to each
cylinder.

2004 Acura TSX

2004 ENGINE PERFORMANCE Fuel & Emissions Systems - TSX

Fig. 35: Cutaway View Of Camshaft Position (CMP) Sensor B

COUNTERSHAFT SPEED SENSOR

This sensor detects countershaft speed.

2004 Acura TSX

2004 ENGINE PERFORMANCE Fuel & Emissions Systems - TSX

Fig. 36: Cutaway View Of Countershaft Speed Sensor

CRANKSHAFT POSITION (CKP) SENSOR

The CKP sensor detects crankshaft speed and is used by the ECM/PCM to determine ignition timing and timing
for fuel injection of each cylinder as well as detecting engine misfire.

2004 Acura TSX

2004 ENGINE PERFORMANCE Fuel & Emissions Systems - TSX

Fig. 37: Cutaway View Of Crankshaft Position (CKP) Sensor

ENGINE COOLANT TEMPERATURE (ECT) SENSOR

The ECT sensor is a temperature dependent resistor (thermistor). The resistance of the thermistor decreases as
the engine coolant temperature increases.

2004 Acura TSX

2004 ENGINE PERFORMANCE Fuel & Emissions Systems - TSX