Last Modified: 7-3-2017 6.8:8.0.40 Doc ID: RM0000018LW009X
Model Year Start: 2007 Model: LX470 Prod Date Range: [08/2006 -           ]
Title: TIRE AND WHEEL: TIRE PRESSURE WARNING SYSTEM: Tire Pressure Warning Light Circuit; 2007 MY LX470 [08/2006 -        ]

Tire Pressure Warning Light Circuit

DESCRIPTION

If the ECU detects trouble, the tire pressure warning light turns on and the tire pressure monitor is canceled at the same time. At this time, the ECU records a DTC in the memory.

Connecting terminals TC and CG of the DLC3 makes the tire pressure warning light blink and output the DTC.

WIRING DIAGRAM

INSPECTION PROCEDURE

NOTICE:

  • When replacing the tire pressure warning ECU and receiver, read the IDs stored in the old ECU using the intelligent tester and write them down before removal.
  • It is necessary to perform initialization 2007 MY LX470 [08/2006 -        ]; TIRE AND WHEEL: TIRE PRESSURE WARNING SYSTEM: INITIALIZATION after registration 2007 MY LX470 [08/2006 -        ]; TIRE AND WHEEL: TIRE PRESSURE WARNING SYSTEM: REGISTRATION of the transmitter IDs into the tire pressure warning ECU and receiver after the ECU has been replaced.

PROCEDURE

1.

INSPECT FUSE

(a) Remove the MET fuse from the cowl side junction block RH.

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

Standard resistance:

Tester Connection

Condition

Specified Condition

MET fuse

Always

Below 1 Ω
OK

GO TO STEP 3

NG

2.

CHECK HARNESS AND CONNECTOR (METER - BODY GROUND)

(a) Disconnect the C14 meter connector.

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

Standard resistance:

Tester Connection

Condition

Specified Condition

C14-10 - Body ground

Always

10 kΩ or higher
NG

REPLACE FUSE AND REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

REPLACE FUSE

3.

CHECK HARNESS AND CONNECTOR (BATTERY - COMBINATION METER)

(a) Disconnect the C14 combination meter connector.

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

Standard voltage:

Tester connection

Switch Condition

Specified Condition

C14-10 - Body ground

Ignition switch ON

10 to 14 V
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

4.

CHECK HARNESS AND CONNECTOR (COMBINATION METER - ECU AND BODY GROUND)

(a) Disconnect the T35 ECU connector.

(b) Disconnect the C15 and C17 meter connector.

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

Standard resistance:

Tester Connection

Condition

Specified Condition

T35-5 (IND) - C15-13

Always

Below 1 Ω

T35-5 (IND) - Body ground

Always

10 kΩ or higher

C17-1 - Body ground

Always

Below 1 Ω
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

5.

OPERATION OF ECU WITH NEW OR NORMAL FUNCTIONING ECU

(a) Temporarily replace the ECU with a new or normally functioning one 2007 MY LX470 [08/2006 -        ]; TIRE AND WHEEL: TIRE PRESSURE WARNING ECU (w/ Receiver): REPLACEMENT .

(b) Perform registration 2007 MY LX470 [08/2006 -        ]; TIRE AND WHEEL: TIRE PRESSURE WARNING SYSTEM: REGISTRATION .

(c) Perform initialization 2007 MY LX470 [08/2006 -        ]; TIRE AND WHEEL: TIRE PRESSURE WARNING SYSTEM: INITIALIZATION after registration.

(d) Check that the malfunction disappears.

OK:

Malfunction disappears

NG

REPLACE COMBINATION METER ASSEMBLY

OK

REPLACE TIRE PRESSURE WARNING ECU AND RECEIVER