Air Conditioning (Diagnostics - Introduction): Diagnosis Lexus GS III facelift

HOW TO PROCEED WITH TROUBLESHOOTING

HINT

1. Use these procedures to troubleshoot the air conditioning system.
2. *: Use the Techstream.

1. VEHICLE BROUGHT TO WORKSHOP NEXT: Go to next step
2. INSPECT BATTERY VOLTAGE Standard 11 to 14 V If the voltage is below 11 V, recharge or replace the battery before proceeding. NEXT: Go to next step
3. CHECK COMMUNICATION FUNCTION OF MULTIPLEX COMMUNICATION SYSTEM (BEAN)* Use the Techstream to check if the Multiplex Communication System (MPX) is functioning normally. Result Result Proceed to MPX DTC is not output A MPX DTC is output B B --> Go to MULTIPLEX COMMUNICATION SYSTEM A: Go to next step
4. CHECK COMMUNICATION FUNCTION OF CAN COMMUNICATION SYSTEM* Use the Techstream to check if the CAN Communication System is functioning normally. Result Result Proceed to CAN DTC is not output A CAN DTC is output B B --> Go to CAN COMMUNICATION SYSTEM A: Go to next step
5. CHECK FOR DTC* Check for DTCs and note any codes that are output. Delete the DTC. Recheck for DTCs. Based on the DTCs output above, try to force output of the A/C system DTC by simulating the operation indicated by the DTC. Result Result Proceed to DTC is not output A DTC is output B B --> Go to step 8 A: Go to next step
6. PROBLEM SYMPTOMS TABLE Refer to «PROBLEM SYMPTOMS TABLE»(ref-382727-S18290080012011012800000) . Result Result Proceed to Fault is not listed in problem symptoms table A Fault is listed in problem symptoms table B B --> Go to step 8 A: Go to next step
7. OVERALL ANALYSIS AND TROUBLESHOOTING* Actuator Check Refer to «ACTUATOR CHECK»(ref-382817-S33297128352011012800000) DATA LIST / ACTIVE TEST. Refer to «DATA LIST / ACTIVE TEST»(ref-382727-S40415579662011012800000) Terminals of ECU. Refer to «TERMINALS OF ECU»(ref-382727-S35529194972011012800000) On-vehicle Inspection Inspection NEXT: Go to next step
8. ADJUST, REPAIR OR REPLACE NEXT --> END

PROBLEM SYMPTOMS TABLE

Scheme 177

Scheme 178

Scheme 179

1. CHECK AIR CONDITIONING AMPLIFIER HINT: Check from the rear of the connector while it is connected to the A/C amplifier. Symbols (Terminal No.) Wiring Color Terminal Description Condition Specified Condition B (K52-1) - Body ground L - Body ground Power source (Back-up) Always 10 to 14 V HTR2 (K52-2) - Body ground (*2) R - Body ground GLW RLY2 relay signal Engine running at 850 rpm or more, ambient temperature 3°C (37.4°F) or less, engine coolant temperature 75°C (167°F) or less, A/C switch setting MAX HOT, blower switch Lo 10 to 14 V SOL+ (K52-5) - Body ground R - Body ground A/C compressor operation signal A/C magnetic clutch on Pulse generation ( see scheme 10waveform 1) S5-1 (K52-7) - SG-1 (K52-19) P - B Power supply for room temperature sensor Engine switch: off Below 1 V Engine switch: on (IG) Approx. 5 V BLW (K52-11) - GND (K52-20) G - W-B Blower motor control signal Engine switch: on (IG) Blower switch: OFF --> ON Pulse generation ( see scheme 11waveform 2) PRE (K52-13) - SG-2 (K52-38) W - V Pressure sensor signal Start engine, operate A/C system Refrigerant pressure: Abnormal pressure (more than 3,030 kPa (31.0 kgf/cm, 440 psi)) 4.7 V or higher PRE (K52-13) - SG-2 (K52-38) W - V Pressure sensor signal Start engine, operate A/C system Refrigerant pressure: Abnormal pressure (less than 180 kPa (1.9 kgf/cm, 27 psi)) Below 0.7 V PRE (K52-13) - SG-2 (K52-38) W - V Pressure sensor signal Start engine, operate A/C system Refrigerant pressure: Normal pressure (less than 3,030 kPa (31.0 kgf/cm, 440 psi) and more than 180 kPa (1.9 kgf/cm, 27 psi)) 0.7 to 4.7 V TSP (K52-14) - GND (K52-20) P - W-B Passenger side solar sensor signal Engine switch: on (IG) Solar sensor subject to electric light 0.8 to 4.3 V RH (K52-15) - SG-1 (K52-19) SB - B Humidity sensor signal Engine switch on (IG), vehicle interior temperature 25°C (77°F), vehicle interior humidity 40% 1.61 to 2.24 V RH (K52-15) - SG-1 (K52-19) SB - B Humidity sensor signal Engine switch on (IG), vehicle interior temperature 25°C (77°F), vehicle interior humidity 60% 2.26 to 2.66 V TR (K52-16) - SG-1 (K52-19) BR - B Room temperature sensor signal Engine switch on (IG), vehicle interior temperature 25°C (77°F) 1.8 to 2.2 V SG-1 (K52-19) - Body ground B - Body ground Ground for room temperature sensor (built-in humidity sensor) Always Below 1 V GND (K52-20) - Body ground W-B - Body ground Ground for main power supply Always Below 1 V IG+ (K52-21) - Body ground W - Body ground Power source (IG) Engine switch: off or on (ACC) Below 1 V Engine switch: on (IG) 10 to 14 V S5-2 (K52-26) - SG-2 (K52-38) Y - V Power supply for pressure sensor Engine switch: on (IG) A/C switch: OFF Below 1 V Engine switch: on (IG) A/C switch: ON Approx. 5 V MPX+ (K52-30) SB Multiplex communication system Multiplex communication circuit - MPX- (K52-31) Y Multiplex communication system Multiplex communication circuit - DGS1 (K52-33) - SG-6 (K52-39) R - GR Exhaust gas sensor signal (NOx) After 30 seconds from engine switch on (IG) and sensor is exposed to exhaust gas 1.0 to 4.5 V DGS (K52-34) - SG-6 (K52-39) L - GR Exhaust gas sensor signal (HC, CO) After 30 seconds from engine switch on (IG) and sensor is exposed to exhaust gas 1.0 to 4.5 V TSD (K52-35) - GND (K52-20) LG - W-B Driver side solar sensor signal Engine switch: on (IG) Solar sensor subject to electric light 0.8 to 4.3 V TAM (K52-36) - SG (K52-37) (*1) V - BR Ambient temperature sensor signal Engine switch: on (IG) at 25°C (77°F) 1.8 to 2.0 V TAM (K52-36) - SG (K52-37) (*1) V - BR Ambient temperature sensor signal Engine switch: on (IG) at 40°C (104°F) 1.4 to 1.6 V SG (K52-37) - Body ground (*1) BR - Body ground Ground for ambient temperature sensor Always Below 1 V SG-2 (K52-38) - Body ground V - Body ground Ground for pressure sensor Always Below 1 V SG-6 (K52-39) - Body ground GR - Body ground Ground for exhaust gas sensor Always Below 1 V HTR1 (K51-13) - Body ground (*2) Y - Body ground GLW RLY1 relay signal Engine running at 850 rpm or more, ambient temperature 3°C (37.4°F) or less, engine coolant temperature 75°C (167°F) or less, A/C switch setting MAX HOT, blower switch Lo 10 to 14 V BUSG (z1-2) - Body ground - Ground for BUS IC Always Below 1 V BUS (z1-3) - BUSG (z1-2) - BUS IC control signal Engine switch: off --> on (IG) Pulse generation BBUS (z1-4) - BUSG (z1-2) - Power supply for BUS IC Engine switch: off Below 1 V Engine switch: on (IG) 10 to 14 V SG (z1-5) - BUSG (z1-2) - Ground for evaporator temperature sensor Always Below 1 V TE (z1-6) - SG (z1-5) - Evaporator temperature sensor signal Engine switch on (IG), temperature near evaporator is 15°C (59°F) 1.4 to 1.8 V *1: for 1UR-FSE *2: for 2GR-FSE Waveform 1: Item Contents Symbols (Terminal No.) SOL+ (K52-5) - Body ground Tool Setting 5 V / DIV., 500 μs / DIV. Vehicle Condition A/C magnetic clutch on Waveform 2: Item Contents Symbols (Terminal No.) BLW (K52-11) - GND (K52-20) Tool Setting 1 V / DIV., 500 μs / DIV. Vehicle Condition Engine switch: on (IG) Blower switch: OFF --> ON HINT: When the blower level is increased, the duty ratio changes accordingly.

Scheme 180

Scheme 181

1. INDICATOR CHECK Turn the engine switch on (IG) while pressing the A/C control AUTO switch and Recirculation / Fresh switch simultaneously. Check that all indicators turn on and off 4 times in succession at 1 second intervals. HINT: After the indicator check is completed, the system enters the DTC mode automatically. Press the "OFF" switch to cancel the indicator check.
2. DTC CHECK USING TECHSTREAM Connect the Techstream to the DLC3. Turn the engine switch on (IG). Turn the Techstream on. Enter the following menus: Body Electrical / Trouble Codes. Check for DTCs.
3. DTC CLEAR USING TECHSTREAM Connect the Techstream to the DLC3. Turn the engine switch on (IG). Turn the Techstream on. Enter the following menus: Body Electrical / Trouble Codes. Erase DTCs by pressing the YES button on the Techstream display.

Scheme 182

Scheme 183

1. LIST OF OPERATION METHODS By operating each of the A/C control switches as shown in the diagram below, it is possible to enter the diagnostic check mode.
2. CHECK DLC3 The vehicle's ECM uses the ISO 15765 - 4 for communication protocol. The terminal arrangement of the DLC3 complies with SAE J1962 and matches the ISO 15765 - 4 format. HINT: Connect the Techstream to the DLC3, turn the engine switch on (IG) and attempt to use the tester. If the display indicates that a communication error has occurred, there is a problem either with the vehicle or with the tester. If communication is normal when the tester is connected to another vehicle, inspect the DLC3 of the original vehicle. If communication is still not possible when the tester is connected to another vehicle, the problem may be in the tester itself. Consult the Service Department listed in the tester's instruction manual. Symbol (Terminal No.) Terminal Description Condition Specified Condition SIL (7) - SG (5) Bus "+" line During transmission Pulse generation CG (4) - Body ground Chassis ground Always Below 1 ohms SG (5) - Body ground Signal ground Always Below 1 ohms BAT (16) - Body ground Battery positive Always 11 to 14 V CANH (6) - CANL (14) HIGH-level CAN bus line Engine switch off 54 to 69 ohms CANH (6) - Battery positive HIGH-level CAN bus line Engine switch off 1 Mohms or higher CANH (6) - CG (4) HIGH-level CAN bus line Engine switch off 3 Mohms or higher CANL (14) - Battery positive LOW-level CAN bus line Engine switch off 1 Mohms or higher CANL (14) - CG (4) LOW-level CAN bus line Engine switch off 3 Mohms or higher

DATA LIST / ACTIVE TEST

1. READ DATA LIST Use the Techstream to read the Data List allows the values or states of switches, sensors, actuators and other items to be read without removing any parts. This non-intrusive inspection can be very useful because intermittent conditions or signals may be discovered before parts or wiring is disturbed. Reading the Data List information early in troubleshooting is one way to save diagnostic time. Connect the Techstream to the DLC3. Turn the engine switch on (IG). Turn the Techstream on. Enter the following menus: for Air Conditioner: Body Electrical / Air Conditioner / Data List. for Engine and ECT: Powertrain / Engine and ECT / Data List. Check the value(s) by referring to the table below. Air Conditioner Tester Display Measurement Item/Range Normal Condition Diagnostic Note Room Temperature Sensor (Room Temp) Room temperature sensor / Min.: -6.5°C (-20.3°F) Max.: 57.25°C (126.95°F) Actual room temperature is displayed - Adjusted Ambient Temp (Ambi Temp) Adjusted ambient temperature / Min.: -30.8°C (-23.44°F) Max.: 50.8°C (123.44°F) - - Ambient Temp Sensor (Ambi Temp Sens) Ambient temperature sensor / Min.: -23.3°C (-9.94°F) Max.: 65.95°C (150.71°F) Actual ambient temperature is displayed - Evaporator Temp Sensor (Evap Temp) Evaporator temperature sensor / Min.: -29.7°C (-21.46°F) Max.: 59.55°C (139.19°F) Actual evaporator temperature is displayed - Solar Sensor (D Side) (Solar Sens-D) Driver side solar sensor / Min.: 0, Max.: 255 Driver side temperature increases as brightness increases - Solar Sensor (P Side) (Solar Sens-P) Passenger side solar sensor / Min.: 0, Max.: 255 Passenger side temperature increases as brightness increases - Engine Coolant Temp (Coolant Temp) Engine coolant temperature / Min.: 1.3°C (34.34°F) Max.: 90.55°C (194.99°F) Actual engine coolant temperature is displayed while engine is warmed up - Set Temperature (D Side) (Set Temp-D) Driver side set temperature / Min.: 17.5°C (63.5°F), Max.: 32.5°C (90.5°F) Driver side actual set temperature is displayed - Set Temperature (P Side) (Set Temp-P) Passenger side set temperature / Min.: 17.5°C (63.5°F), Max.: 32.5°C (90.5°F) Passenger side actual set temperature is displayed - Estimated Temp (D Side) (Estimate Temp-D) Driver side estimated temperature / Min.: -358.4°C (-613.12°F) Max.: 358.4°C (677.12°F) Driver side actual estimated temperature is displayed - Estimated Temp (P Side) (Estimate Temp-P) Passenger side estimated temperature / Min.: -358.4°C (-613.12°F) Max.: 358.4°C (677.12°F) Passenger side actual estimated temperature is displayed - Hand Free Telephone (Hand Free Tel) Hands free telephone / OFF or ON - - Blower Motor Speed Level (Blower Level) Blower motor speed level / Min.: 0 level, Max.: 31 level Increases in the range between 0 and 31 as the blower motor speed increases - Emission Gas Sensor (Emiss Gas Sens) Emission gas / Min.: 0, Max.: 255 Increases as the gas amount increases - Destination (Destination) Destination / Domest, USA, Austral, Mideast, No Info, Europe Changes value with destinations - Emission Gas Nox Sensor (Nox Gas Sens) Emission gas / Min.: 0, Max.: 255 Increases as gas amount increases - Regulator Pressure Sensor (Reg Press Sens) Regulator pressure sensor / Min.: -0.45668 MPaG, Max.: 3.29437 MPaG Actual regulator pressure is displayed - Regulator Control Current (Reg Ctrl Currnt) Regulator control current / Min.: 0 A, Max.: 255 A - - Humidity Sensor (Humidity Sens) Humidity sensor / Min.: 0%, Max.: 100% Actual room humidity is displayed - Air Mix Servo Targ Pulse(D) (Air Mix Pulse-D) Driver side air mix servomotor target pulse / Min.: 0, Max.: 255 Customized value will be displayed - Air Mix Servo Targ Pulse(P) (Air Mix Pulse-P)) Passenger side air mix servomotor target pulse / Min.: 0, Max.: 255 Customized value will be displayed - Air Outlet Servo Pulse (D) (Air Out Pulse-D) Driver side air outlet servomotor target pulse / Min.: 0, Max.: 255 Customized value will be displayed - Air Inlet Damper Targ Pulse (A/I Damp Targ Pls) Air inlet damper target pulse / Min.: 0, Max.: 255 Customized value will be displayed - Cool Air Bypass Pulse (A/B Damp Pls) Driver side cool air bypass pulse / Min.: 0, Max.: 255 Customized value will be displayed - Number of Trouble Codes (#Codes) Number of trouble codes / Min.: 0, Max.: 255 Number of DTCs will be displayed - Engine and ECT Tester Display Measurement Item/Range Normal Condition Diagnostic Note A/C SIG (A/C SIG) A/C signal / ON or OFF ON: A/C ON OFF: A/C OFF - A/C MAG Clutch (A/C MAG CLUTCH) A/C magnetic clutch relay / OFF, ON ON: A/C magnetic clutch ON OFF: A/C magnetic clutch OFF
2. PERFORM ACTIVE TEST Use the Techstream to perform Active Tests allows the relay, actuator, and other items to operate without removing any parts. This non-intrusive functional inspection can be very useful because intermittent operation may be discovered before parts or wiring is disturbed. Performing Active Test early in troubleshooting is one way to save diagnostic time. Data List information can be display while performing Active Test. Connect the Techstream to the DLC3. Turn the engine switch on (IG). Turn the Techstream on. Enter the following menus: for Air Conditioner: Body Electrical / Air Conditioner / Active Test. for Engine and ECT: Powertrain / Engine and ECT / Active Test. Check the operation by referring to the table below. Air Conditioner Tester Display Test Part Control Range Diagnostic Note Blower Motor (Blower Motor) Blower motor Min.: Level 0, Max.: Level 31 - Magnetic Clutch Relay (A/C Mag Clutch) Magnetic clutch relay OFF, ON - Defogger Relay (Rear) (Defogger Rly-R) Defogger relay (Rear) OFF, ON - Deicer Relay (Front) (Deicer Rly (Ft)) Deicer relay (Front) OFF, ON - Electric Heater1 (Heater1) Electric Heater 1 OFF, ON - Electric Heater2 (Heater2) Electric Heater 2 OFF, ON - Air Mix Servo Targ Pulse(D) (Air Mix Pulse-D) Driver side air mix servomotor pulse Min.: 0, Max.: 255 - Air Mix Servo Targ Pulse(P) (Air Mix Pulse-P) Passenger side air mix servomotor pulse Min.: 0, Max.: 255 - Air Outlet Servo Pulse (D) (Air Out Pulse-D) Driver side air outlet servomotor pulse Min.: 0, Max.: 255 - Air Inlet Damper Targ Pulse (A/I Damp Targ Pls) Air inlet damper target pulse Min.: 0, Max.: 255 - Cool Air Bypass Pulse (A/B Damp Pls) Cool air bypass pulse Min.: 0, Max.: 255 - Engine and ECT Tester Display Test Part Control Range Diagnostic Note A/C Magnetic Clutch Relay (A/C MAG CLUTCH) Magnetic clutch relay OFF, ON

DIAGNOSTIC TROUBLE CODE CHART

*1: for 2GR-FSE