Circuit Test B6 - Vane Airflow (VAF) Meter

Fig 1: VAF Meter Circuits

NOTE: Enter this test only when a Code 08 is displayed during the QUICK TEST procedure or when directed here from another CIRCUIT TEST. To prevent replacement of good components, be aware that the following non-EEC items may be at fault: unmetered air leaks between VAF meter and throttle body. Vacuum leaks. Engine seals (PCV seals, valve cover, dipstick). This test is intended to diagnose only the following components: VAF meter, ECA, and wiring harness circuits (VREF, VAF signal and signal return).

Checking System Integrity - Visually check all wiring, harnesses, connectors and components for evidence of damage, overheating, shorting or looseness. If a fault is found, repair as necessary. If no faults are found, go to next step.
Checking Voltage to VAF Meter - Install breakout box and set VOM on 20-volt scale. Leave ECA disconnected. Turn key on. Measure voltage between test pins No. 18 and 20 (ground). If voltage is 7-9 volts, go to step 6). If not, go to next step.
Checking Voltage at VAF Meter - Leave VAF meter connected. DO NOT pierce wire, carefully backprobe harness connector. Set VOM on 20-volt scale. Turn key on. Measure voltage between terminal "E" at VAF meter ("R/W" wire) and ground. If voltage is 7-9 volts, repair open or short in "R/W" wire between VAF meter and ECA. If voltage is not 7-9 volts, go to next step.
Checking Voltage at VAF Meter - Leave VAF meter connected. DO NOT pierce wire, carefully backprobe harness connector. Set VOM on 20-volt scale. Turn key on. Measure voltage between terminal "D" at VAF meter ("R/BK" wire) and ground. If voltage is greater than 10 volts, replace VAF meter. If voltage is less than 10 volts, go to next step.
Checking Power to Relay No. 2 - DO NOT disconnect relay or pierce wire. Set VOM on 20-volt scale. Turn key on. Measure voltage between "R/BK" wire at relay No. 2, and ground. If voltage is greater than 10.0 volts, repair open or short in "R/BK" wire from relay to VAF meter. If voltage is 10.0 or less, go to CIRCUIT TEST B12, step 1).
Checking Signal Return Circuit - Turn key off, and install breakout box. Set VOM on 200-ohm scale. Measure resistance between test pins No. 46 and 20 (ground). If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, go to CIRCUIT TEST A3 , step 1).
Checking Signal Return at VAF Meter - Turn key off, and install breakout box. Set VOM on 200-ohm scale. Measure resistance between "LG/Y" wire at VAF meter terminal "C" and test pin No. 46. If resistance is less than 5 ohms, go to next step. If not, repair open in "LG/Y" wire between VAF meter and ECA.

Checking VAF Meter Voltage - Install breakout box and set VOM on 20-volt scale. Perform the following KOEO and KOER (engine at idle) checks:

VAF VOLTAGE at BREAKOUT BOX

Circuit	KOEO	KOER (Idle)
Test pins No. 43 & 20	1.7 volts	4-6 volts
Test pins No. 43 & 46	1.7 volts	4-6 volts
Test pins No. 20 & 46	0 volts	0 volts

Checking VAF Meter Signal - Leave breakout box connected. DO NOT pierce wire. Set VOM on 20-volt scale. Perform the following KOEO and KOER (engine at idle) checks. If all readings are within specifications repair "R/BK" wire from VAF meter to ECA. If readings are not within specifications, replace VAF meter.

VAF METER VOLTAGE at METER

Circuit	KOEO	KOER (Idle)
Terminal "F" ("R/BK" wire) to ground	1.7 volts	4-6 volts
Terminal "C" ("LG/Y" wire) to ground	0 volts	0 volts
Terminals "C" to "F" and ground	1.7 volts	4-6 volts