Canada - A/C - Warm Air From Vents With A/C On
BulletinTSB2757
Issue Date
December 16, 2009
Title
WARM AIR FROM HVAC VENTS WITH A/C ON - DTC B1479
Component
HEATING/ AIR CONDITIONING
Models
'10 RX350
INTRODUCTION:
Some RX 350 vehicles may exhibit a condition where the HVAC system intermittently blows warm air from the vents with the A/C on.
Diagnostic Trouble Code (DTC) B1479 (Flow Sensor Circuit) may be stored in the A/C system as either a Current or History DTC. A malfunctioning A/C compressor flow sensor may cause this condition.
Follow the procedure in this TSB to determine if this service bulletin is applicable and to repair the vehicle.
APPLICABILITY:
PRODUCTION CHANGE INFORMATION:
This TSB applies to vehicles produced BEFORE the Production Change Effective VIN shown below.
WARRANTY INFORMATION:
PARTS INFORMATION:
REQUIRED TOOLS & EQUIPMENT:
REPAIR PROCEDURE:
1. Using ETAS Techstream, check for diagnostic trouble codes (DTCs) in the A/C system.
- If DTC B1479 is stored as a Current or History DTC, go to step 2.
- If DTC B1479 is NOT stored as Current or History, this TSB does NOT apply. Refer to the problem symptoms table of the Repair Manual.
Refer to the Repair Manual within E-TAS / TIS library:
- Division: Lexus
- Model: RX350
- Year: 2010
- Service Category: Vehicle Interior
- Section: Heating/Air Conditioning
- Keyword: Air Conditioning System/ Problem Symptoms Table
2. Using Techstream, inspect the the flow sensor.
- If the flow sensor value does NOT change when switching the A/C system/blower ON and OFF, and is stuck between 0.7 and 4.0 V, go to step 4.
- If the flow sensor voltage is normal, go to step 3 (wire harness check).
3. Check the harness and connector (A/C compressor flow sensor - A/C amplifier).
A. Disconnect the A/C amplifier connector.
B. Measure the resistance according to the value(s) in the table below.
Standard Resistance:
- If any of the harness resistance tests fail, this TSB does NOT apply.
Repair or replace the harness and go to step 5.
- If all tests are within specifications, proceed to step 4.
4. Remove and replace the A/C compressor.
Refer to the Repair Manual within E-TAS / TIS library:
- Division: Lexus
- Model: RX350
- Year: 2010
- Service Category: Vehicle Interior
- Section: Heating/Air Conditioning
- Keyword: Heating/Air Conditioning: Compressor: Removal/Installation
5. Clear all DTCs and confirm the A/C system has returned to proper operation.
NOTE:
Issue of this Technical Service Bulletin is to ensure that proper repair information is available. IT DOES NOT CONSTITUTE AN AUTHORIZATION FOR REPAIR. Normal provisions of the formal warranty policy, as applicable, will apply.