Lexus NX: Problem Symptoms Table

PROBLEM SYMPTOMS TABLE

NOTICE:

  • If the auxiliary battery voltage is low, the PTC heater, seat heater system (w/ Seat Heater System) and climate control seat system (w/ Climate Control Seat System) may not operate. When "High Power Consumption Partial Limit On AC/Heater Operation." is displayed on the multi-information display in the combination meter assembly, inspect the auxiliary battery, referring to On-vehicle Inspection for the charging system.

    Click here

    HINT:

    If the auxiliary battery voltage is low, "Operation Limitation Control History Count (Level 1)" and "Operation Limitation Control History Count (Level 2) is counted.

    Click here

    • PTC Heater
    • Seat heater system (w/ Seat Heater System)

      If the seat heater system does not operate normally, refer to the troubleshooting.

      Click here

    • Climate control seat system (w/ Climate Control Seat System)

      If the climate control seat system does not operate normally, refer to the troubleshooting.

      Click here

  • If the auxiliary battery voltage is low, the PTC heater may not operate. Refer to Data List for the power steering system.
    • for Manual Tilt and Manual Telescopic Steering Column

      Click here

    • for Power Tilt and Power Telescopic Steering Column

      Click here

  • When the auxiliary battery is disconnected, or servo motor or the air conditioning amplifier assembly is replaced, be sure to perform servo motor initialization.

    Click here

HINT:

  • Use the table below to help determine the cause of problem symptoms. If multiple suspected areas are listed, the potential causes of the symptoms are listed in order of probability in the "Suspected Area" column of the table. Check each symptom by checking the suspected areas in the order they are listed. Replace parts as necessary.
  • Inspect the fuses and relays related to this system before inspecting the suspected areas below.
Air Conditioning System

Symptom

Suspected Area

Link

All functions of the air conditioning system do not operate.

IG power source circuit

Back-up power source circuit

LIN communication circuit

Air conditioning amplifier assembly

Air flow control: No blower operation.

Blower motor circuit

Air conditioning control assembly

Air conditioning amplifier assembly

Air flow control: No blower control.

Blower motor circuit

Air conditioning control assembly

Air conditioning amplifier assembly

Air flow control: Insufficient air flow.

Blower motor circuit

Air conditioning amplifier assembly

Temperature control: Cooling effectiveness is poor.

Refrigerant gas volume check using the Techstream

Refrigerant volume

Refrigerant pressure

Cooler expansion valve

Compressor with motor assembly

Air conditioning amplifier assembly

Temperature control: No cool air comes out.

Refrigerant gas volume check using the Techstream

Refrigerant volume

Refrigerant pressure

Air conditioner pressure sensor circuit

Air mix damper control servo motor circuit (for driver side)

Air mix damper control servo motor circuit (for front passenger side)

Evaporator temperature sensor circuit

Room temperature sensor circuit

Ambient temperature sensor circuit

Check customize setting "Set Temperature Shift"

LIN communication circuit

Cooler expansion valve

No. 1 air conditioning radiator damper servo sub-assembly

Air conditioning harness assembly

Engine wire

Compressor with motor assembly

Air conditioning amplifier assembly

Hybrid vehicle control ECU

Inverter with converter assembly

ECM

Temperature control: No warm air comes out.

Air mix damper control servo motor circuit (for driver side)

Air mix damper control servo motor circuit (for front passenger side)

Evaporator temperature sensor circuit

Room temperature sensor circuit

Ambient temperature sensor circuit

Heater water pump circuit

Check customize setting "Set Temperature Shift"

LIN communication circuit

No. 1 air conditioning radiator damper servo sub-assembly

Air conditioning harness assembly

Radiator unit sub-assembly

Air conditioning amplifier assembly

Hybrid vehicle control ECU

ECM

Temperature control: Output air is warmer or cooler than the set temperature or response is slow.

Refrigerant gas volume check using the Techstream

Refrigerant volume

Refrigerant pressure

Solar sensor circuit (for driver side) (for Triple Beam Headlight)

Solar sensor circuit (for driver side) (for Single Beam Headlight)

Solar sensor circuit (for front passenger side) (for Triple Beam Headlight)

Solar sensor circuit (for front passenger side) (for Single Beam Headlight)

Room temperature sensor circuit

Ambient temperature sensor circuit

Air mix damper control servo motor circuit (for driver side)

Air mix damper control servo motor circuit (for front passenger side)

Air inlet damper control servo motor circuit

LIN communication circuit

Radiator unit sub-assembly

Cooler expansion valve

No. 1 air conditioning radiator damper servo sub-assembly

No. 1 blower damper servo sub-assembly

Air conditioning harness assembly

Air conditioning amplifier assembly

Hybrid vehicle control ECU

ECM

Temperature control: No temperature control. (only Max. cool or Max. hot)

Air mix damper control servo motor circuit (for driver side)

Air mix damper control servo motor circuit (for front Passenger side)

Room temperature sensor circuit

Ambient temperature sensor circuit

Evaporator temperature sensor circuit

Solar sensor circuit (for driver side) (for Triple Beam Headlight)

Solar sensor circuit (for driver side) (for Single Beam Headlight)

Solar sensor circuit (for front passenger side) (for Triple Beam Headlight)

Solar sensor circuit (for front passenger side) (for Single Beam Headlight)

LIN communication circuit

No. 1 air conditioning radiator damper servo sub-assembly

Air conditioning harness assembly

Air conditioning amplifier assembly

No air inlet control.

Air inlet damper control servo motor circuit

LIN communication circuit

No. 1 blower damper servo sub-assembly

No. 1 air conditioning radiator damper servo sub-assembly

Air conditioning harness assembly

Air conditioning amplifier assembly

No air flow mode control.

Air outlet damper control servo motor circuit

Rear air outlet damper control servo motor circuit

LIN communication circuit

No. 1 air conditioning radiator damper servo sub-assembly

No. 2 air conditioning radiator damper servo sub-assembly

Air conditioning harness assembly

Air conditioning amplifier assembly

Quick heater assembly does not operate.

"High Power Consumption Partial Limit On AC/Heater Operation" message does not display on the multi-information display in combination meter assembly.

-

PTC heater circuit

Air conditioning amplifier assembly

Hybrid vehicle control ECU

ECM

Integration control and panel assembly (ECO mode switch) does not operate normally.

ECO switch circuit

Air conditioning amplifier assembly

Diagnostic trouble codes (DTCs) are not recorded. Set mode is cleared when power switch is off.

Back-up power source circuit

Air conditioning amplifier assembly

READ NEXT:

 Dtc Check / Clear

DTC CHECK / CLEAR DTC CHECK USING TECHSTREAM (a) Connect the Techstream to the DLC3. (b) Turn the power switch on (IG). (c) Turn the Techstream on. (d) Enter the following menus: Body Electrical / Air

 Terminals Of Ecu

TERMINALS OF ECU AIR CONDITIONING AMPLIFIER ASSEMBLY (a) Disconnect the I50 air conditioning amplifier assembly connector. (b) Measure the resistance and voltage according to the value(s) in the tabl

 Check Mode Procedure

CHECK MODE PROCEDURE REFRIGERANT GAS VOLUME CHECK IN NORMAL OPERATION (CHECK A/C SWITCH INDICATOR AND DTC) *a Example (a) Turn the power switch on (READY). (b) Check that A/C switch indicator

SEE MORE:

 Removal

REMOVAL CAUTION / NOTICE / HINT HINT: Use the same procedure for the RH and LH sides. The procedure listed below is for the LH side. PROCEDURE 1. REMOVE TONNEAU COVER ASSEMBLY Click here 2. REMOVE DECK BOARD ASSEMBLY Click here 3. REMOVE NO. 3 DECK BOARD SUB-ASSEMBLY Click here

 Problem Symptoms Table

PROBLEM SYMPTOMS TABLE HINT: Use the table below to help determine the cause of problem symptoms. If multiple suspected areas are listed, the potential causes of the symptoms are listed in order of probability in the "Suspected Area" column of the table. Check each symptom by checking the suspect

© 2016-2024 Copyright www.lexunx.com