Section 501 (Climate Control Seat System): Inspection

WARNING: This page is about a different car, the 2003 Lexus LS 430. However, it is still accessible from the selected car via links, so may be relevant.

INSPECT CLIMATE CONTROL SWITCH INDICATOR OPERATION
1. Connect the positive (+) lead from the battery to terminal 14 and negative (-) lead to terminal 6.
2. Check that the indicator lights up when climate controls witch is turned ON.
  If climate indicator does not light up, replace climate control switch.
  
  Fig 1: Inspecting Climate Control Switch Indicator Operation
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

INSPECT CLIMATE CONTROL SWITCH OPERATION

(): Front passenger side:
Measure resistance between terminals 1 (15) and 13 (17) is approx. 5.0 kΩ

(): Front passenger side:

Measure resistance between terminals 12 (16) and 13 (17) at switch each position as shown in the chart.

RESISTANCE SPECIFICATIONS

Switch position	Resistance
Max. COOL	0 kΩ
Max. WARM	5 kΩ

If resistance is not as specified, replace the climate control switch.

INSPECT CLIMATE CONTROL SWITCH CIRCUIT

Disconnect the connector from the climate control switch and inspect the connector on the wire harness side, as shown in the chart below.

Fig 2: Identifying Climate Control Switch Connector Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

CONNECTOR TERMINALS SPECIFIED CONDITION

Tester connection	Condition	Specified condition
6 - Ground	Constant	Continuity
14 - Ground	Turn ignition switch ON	Battery positive voltage
14 - Ground	Turn ignition switch LOCK or ACC	No voltage

If the circuit is not as specified, replace the wire harness.

INSPECT THERMISTOR RESISTANCE

(): Seat cushion side:

Measure resistance between terminals 2 (1)and 3 (2) of climate controller at each temperature, as shown in the chart.

RESISTANCE SPECIFICATIONS

Temperature °C (°F)	Resistance kΩ
10 °C (50°F)	Approx. 3.7 kΩ
25 °C (77°F)	Approx. 2 Ω
30 °C (86°F)	Approx. 1.7 kΩ

HINT:

As the temperature increase, the resistance decreases. If the resistance is not as specified, replace the climate controller

Fig 3: Inspecting Thermistor Resistance

INSPECT CLIMATE CONTROL ECU CIRCUIT

Disconnect the connector from the climate control ECU and inspect connector on the wire harness side, as shown in the chart.

Fig 4: Disconnecting Connector From Climate Control ECU

CONNECTOR TERMINALS SPECIFIED CONDITION

Tester connection	Condition	Specified condition
8 - Ground	Constant	Continuity
7 - Ground	Turn ignition switch ON	Battery positive voltage
7 - Ground	Turn ignition switch OFF	No voltage

If circuit is not as specified, replace the repair or replace the wire harness.