Toyota CH-R Service Manual: Power Source Circuit

DESCRIPTION

When the ignition switch is ON or the operation conditions of the headlights are met, the main body ECU (multiplex network body ECU) supplies power to the headlight ECU sub-assemblies via the No. 1 integration relay.

When the ignition switch is ON, the main body ECU (multiplex network body ECU) supplies power to the headlight ECU sub-assemblies via the IG1-NO. 1 relay.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

PROCEDURE

1.	CHECK HARNESS AND CONNECTOR (HEADLIGHT ECU SUB-ASSEMBLY - POWER SOURCE AND BODY GROUND)

(a) Disconnect the A16 headlight ECU sub-assembly LH connector.

(b) Disconnect the A17 headlight ECU sub-assembly RH connector.

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

Standard Voltage:

Headlight ECU Sub-assembly LH

Tester Connection	Switch Condition	Specified Condition
A16-13 (ECUB) - Body ground	Ignition switch ON	11 to 14 V
A16-4 (IG) - Body ground	Ignition switch ON	11 to 14 V

Headlight ECU Sub-assembly RH

Tester Connection	Switch Condition	Specified Condition
A17-13 (ECUB) - Body ground	Ignition switch ON	11 to 14 V
A17-4 (IG) - Body ground	Ignition switch ON	11 to 14 V

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

Standard Resistance:

Headlight ECU Sub-assembly LH

Tester Connection	Condition	Specified Condition
A16-12 (GND) - Body ground	Always	Below 1 Ω

Headlight ECU Sub-assembly RH

Tester Connection	Condition	Specified Condition
A17-12 (GND) - Body ground	Always	Below 1 Ω

Result	Proceed to
OK	A
NG (Headlight ECU Sub-assembly LH)	B
NG (Headlight ECU Sub-assembly RH)	C

A

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

C

GO TO STEP 6

B

2.	INSPECT NO. 1 INTEGRATION RELAY (H-LP LH RELAY)

(a) Remove the No. 1 integration relay from the No. 1 engine room relay block.

Click here

(b) Inspect the No. 1 integration relay.

Click here

OK:

No. 1 integration relay is normal.

NG

REPLACE NO. 1 INTEGRATION RELAY

OK

3.	CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY (H-LP LH RELAY) - BATTERY)

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

Standard Voltage:

Tester Connection	Condition	Specified Condition
1A-5 - Body ground	Always	11 to 14 V

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

4.	CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)

(a) Disconnect the 3F instrument panel junction block assembly connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
1B-2 - 3F-31	Always	Below 1 Ω
1B-2 or 3F-31 - Body ground	Always	10 kΩ or higher

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

5.	INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

(a) Remove the instrument panel junction block assembly.

Click here

(b) Remove the main body ECU (multiplex network body ECU) from the instrument panel junction block assembly.

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

*a

Component without harness connected (Instrument Panel Junction Block Assembly)

-

-

Standard Resistance:

Tester Connection	Condition	Specified Condition
3F-31 - MB-15 (HRLY)	Always	Below 1 Ω

OK

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

NG

REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

6.	INSPECT NO. 1 INTEGRATION RELAY (H-LP RH RELAY)

(a) Remove the No. 1 integration relay from the No. 1 engine room relay block.

Click here

(b) Inspect the No. 1 integration relay.

Click here

OK:

No. 1 integration relay is normal.

NG

REPLACE NO. 1 INTEGRATION RELAY

OK

7.	CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY (H-LP RH RELAY) - BATTERY)

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

Standard Voltage:

Tester Connection	Condition	Specified Condition
1B-8 - Body ground	Always	11 to 14 V

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

8.	CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU))

(a) Disconnect the F15 main body ECU (multiplex network body ECU) connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
1A-11 - F15-1 (DIM)	Always	Below 1 Ω
1A-11 or F15-1 (DIM) - Body ground	Always	10 kΩ or higher

OK

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR