DTC B1479/79: Flow Sensor Circuit: Procedure

1. Connect the Techstream to the DLC3.
2. Turn the ignition switch to ON.
3. Turn the Techstream on.
4. Enter the following menus: Body / Air Conditioner / Data List.
5. Check the value(s) by referring to the table below.
   AIR CONDITIONER
   
   

   Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
   Flow Sensor (Flow Sens)	A/C flow sensor / Min.: 0 V Max.: 5 V	A/C on, Blower switch HI: 0.7 to 3.8 V A/C off, Blower switch off: 3.8 to 4.2 V	A/C flow sensor is malfunctioning when a constant value below 0.7 V or higher than 4.2 V is displayed continuously for more than 4 seconds.

   OK

   The display is as specified in the Normal Condition column.

   Result

   Result	Proceed to
   OK (When troubleshooting according to Problem Symptoms Table)	A
   OK (When troubleshooting according to the DTC)	B
   NG (When a constant value below 0.3 V or higher than 4.7 V is displayed continuously for more than 4 seconds)	C

C → See step   3 

B → See step   5 

A: Go to next step 

1. Connect the Techstream to the DLC3.
2. Turn the ignition switch to ON.
3. Turn the Techstream on.
4. Enter the following menus: Body / Air Conditioner / Data List.
5. Check the value(s) by referring to the table below.
   AIR CONDITIONER
   
   

   Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
   A/C Cutoff Signal	A/C control cutoff signal / OFF or ON	A/C switch on: OFF A/C switch off: ON	-

   Result

   Result	Proceed to
   Operation does not match normal condition column	A
   Operation matches normal condition column	B

B → See step   6 

A: Go to next step 

1. Replace the compressor assembly with pulley (A/C flow sensor). Refer to REMOVAL .

   HINT: 

   Since the compressor assembly with pulley (A/C flow sensor) cannot be inspected while it is removed from the vehicle, replace the compressor assembly with pulley (A/C flow sensor) with a new or a known good one and check that the condition returns to normal.

2. Check for the DTC.

   Result

   Result	Proceed to
   DTC B1479/79 is not output	A
   DTC B1479/79 is output	B

B → See step   4 

A → END 

1. Disconnect the A/C amplifier connector.
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   E30-7 (FLOQ) - B97-3 (QUFL)	Always	Below 1 Ω
   E30-35 (SG-4) - B97-2 (SGFL)	Always	Below 1 Ω
   E30-30 (S5-1) - B97-1 (S5FL)	Always	Below 1 Ω
   E30-7 (FLOQ) - Body ground	Always	10 kΩ or higher
   E30-35 (SG-4) - Body ground	Always	10 kΩ or higher
   E30-30 (S5-1) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   5