Last Modified: 11-29-2007 1.6 G
Service Category: Vehicle Interior Section: Seat
Model Year: 2008 Model: Sequoia Doc ID: RM000003F7K000X
Title: SEAT: SEAT HEATER SYSTEM: ON-VEHICLE INSPECTION (2008 Sequoia)

ON-VEHICLE INSPECTION

1. INSPECT SEAT HEATER CONTROL SUB-ASSEMBLY LH (for Front Seat)

(a) Disconnect the X12 heater control connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

X12-6 (E) - Body ground

Always

Below 1 Ω

If the result is not as specified, there may be a malfunction on the wire harness side.

(c) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection

Switch Condition

Specified Condition

X12-1 (SWL) - X12-6 (E)

Ignition switch ON

Seat heater switch OFF

Below 1 V

Ignition switch ON

Seat heater switch ON

11 to 14 V

X12-4 (B) - X12-6 (E)

Ignition switch OFF

Below 1 V

Ignition switch ON

11 to 14 V

If the result is not as specified, there may be a malfunction on the wire harness side.

(d) Connect the X12 heater control connector.

(e) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection

Switch Condition

Specified Condition

X12-5 (THL) - Body ground

Ignition switch ON

Seat heater switch ON, volume MIN → MAX (for Limited and SR5 grade)

Seat heater switch ON, volume 1 → 3 (for Platinum grade)

Gradual increase between below 1 V and 11 to 14 V

If the result is not as specified, the seat heater control may have a malfunction.

2. INSPECT SEAT HEATER CONTROL SUB-ASSEMBLY RH (for Front Seat)

(a) Disconnect the W8 heater control connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

W8-6 (E) - Body ground

Always

Below 1 Ω

If the result is not as specified, there may be a malfunction on the wire harness side.

(c) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection

Switch Condition

Specified Condition

W8-1 (SWR) - W8-6 (E)

Ignition switch ON

Seat heater switch OFF

Below 1 V

Ignition switch ON

Seat heater switch ON

11 to 14 V

W8-4 (B1) - W8-6 (E)

Ignition switch OFF

Below 1 V

Ignition switch ON

11 to 14 V

If the result is not as specified, there may be a malfunction on the wire harness side.

(d) Connect the W8 heater control connector.

(e) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection

Switch Condition

Specified Condition

W8-5 (THR) - Body ground

Ignition switch ON

Seat heater switch ON, volume MIN → MAX (for Limited and SR5 grade)

Seat heater switch ON, volume 1 → 3 (for Platinum grade)

Gradual increase between below 1 V and 11 to 14 V

If the result is not as specified, the seat heater control may have a malfunction.

3. INSPECT SEAT HEATER CONTROL SUB-ASSEMBLY LH (for Rear No. 1 Seat)

(a) Disconnect the O43 heater control connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

O43-10 (SWL) - O43-13 (E)

Seat heater LO switch OFF

10 kΩ or higher

Seat heater LO switch ON

Below 1 Ω

O43-12 (HIL) - O43-13 (E)

Seat heater HI switch OFF

10 kΩ or higher

Seat heater HI switch ON

Below 1 Ω

O43-13 (E) - Body ground

Always

Below 1 Ω

If the result is not as specified, there may be a malfunction on the wire harness side.

(c) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection

Condition

Specified Condition

O43-1 (B) - O43-13 (E)

Always

11 to 14 V

If the result is not as specified, there may be a malfunction on the wire harness side.

(d) Connect the O43 heater control connector.

(e) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection

Switch Condition

Specified Condition

1 - Body ground

Ignition switch ON

Seat heater switch OFF

Below 1 V

Ignition switch ON

Seat heater LO or HI switch ON

11 to 14 V

HINT:

4. INSPECT SEAT HEATER CONTROL SUB-ASSEMBLY RH (for Rear No. 1 Seat)

(a) Disconnect the P23 heater control connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

P23-10 (SWR) - P23-13 (TC)

Seat heater LO switch OFF

10 kΩ or higher

Seat heater LO switch ON

Below 1 Ω

P23-12 (HIR) - P23-13 (TC)

Seat heater HI switch OFF

10 kΩ or higher

Seat heater HI switch ON

Below 1 Ω

P23-13 (TC) - Body ground

Always

Below 1 Ω

If the result is not as specified, there may be a malfunction on the wire harness side.

(c) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection

Condition

Specified Condition

P23-1 (B1) - P23-13 (TC)

Always

11 to 14 V

If the result is not as specified, there may be a malfunction on the wire harness side.

(d) Connect the P23 heater control connector.

(e) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection

Switch Condition

Specified Condition

1 - Body ground

Ignition switch ON

Seat heater switch OFF

Below 1 V

Ignition switch ON

Seat heater LO or HI switch ON

11 to 14 V

HINT: