CKT Test MC-VAF - Measuring Core-Volume Airflow Sensor

WARNING: This page is about a different variant/trim than selected.

Fig 1: MC-VAF Sensor Circuit & Conn. Terminal ID (MC-VAF - 2.5L)

NOTE: Enter this test only when a Code 08 is displayed during self-test procedures (KOEO or KOER) or when directed here from another circuit test. To avoid unnecessary use of diagnostic time, check for unmetered air leaks between MC-VAF meter and throttle body. This test is intended to diagnose MC-VAF circuit only.

CIRCUIT PIN IDENTIFICATION

Circuit	Breakout Box Pin No.	PCM Pin	Wire Color
GND	46	3D	Black/Blue
MC-VAF	44	2B	Red
VREF	26	2I	Purple

1) Check System Integrity Visually check all wiring, connectors and components for evidence of damage, shorting or looseness. If fault is found, repair as necessary. If no fault is found, go to next step.

2) Check MC-VAF Sensor Input Voltage To PCM Turn ignition off. Install breakout box. Connect PCM to breakout box. Access MC-VAF sensor in air cleaner. Turn ignition on. Measure voltage between MC-VAF and GND test pins at breakout box while moving MC-VAF measuring core. Compare voltage readings with VOLTAGE SPECIFICATIONS (MC-VAF METER) table. If voltage is as specified, MC-VAF circuit is okay. Replace PCM. If voltage is not as specified, go to next step.

VOLTAGE SPECIFICATIONS

Measuring Core Position	Volts
Closed	4.0
1/4 Open	2.4
1/2 Open	1.6
3/4 Open	0.8
Fully Open	0.4

3) Check VREF At MC-VAF Sensor Turn ignition off. Disconnect MC-VAF sensor connector. Turn ignition on. Measure voltage at VREF terminal at MC-VAF sensor connector. If voltage is 4.5-5.5 volts, go to next step. If voltage is not 4.5-5.5 volts, go to CIRCUIT TEST VREF.

4) Check For An Open MC-VAF Wire Turn ignition off. With breakout box installed, disconnect PCM. Ensure MC-VAF sensor is disconnected. Measure resistance at MC-VAF test pin at breakout box and MC-VAF terminal at MC-VAF sensor connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open MC-VAF wire.

5) Check For Short In MC-VAF Wire Turn ignition off. Ensure breakout box is installed and PCM and MC-VAF sensor are disconnected. Measure resistance between ground and MC-VAF test pin at breakout box. If resistance is more than 10,000 ohms, go to next step. If resistance is 10,000 ohms or less, repair short to ground in MC-VAF wire.

6) Check MC-VAF Sensor Ground Turn ignition off. Ensure MC-VAF is disconnected. Measure resistance between GND test pin at breakout box and GND terminal at MC-VAF sensor connector. If resistance is less than 5 ohms, replace MC-VAF sensor. If resistance is 5 ohms or more, repair open GND wire.