DTC 74-40: Short in Speaker Circuit: Procedure

CHECK DTC
1. Disconnect the stereo component amplifier assembly connector O17*1 or O34*2 and disconnect connector O16.
  - *1: for 12 Speakers
  - *2: for 9 Speakers
2. Clear the DTCs and recheck for DTCs.
3. Check if DTC 74-40 is output.
  OK
  
  DTC 74-40 is not output.
NG → See step 17

OK: Go to next step
CHECK OPERATION
1. Reconnect stereo component amplifier assembly connector O17*1 or O34*2.
  - *1: for 12 Speakers
  - *2: for 9 Speakers
2. Check if DTC 74-40 is output.
  OK
  
  DTC 74-40 is not output.
NG → See step 8

OK: Go to next step

CHECK HARNESS AND CONNECTOR

Disconnect the connectors shown in the illustration from the stereo component amplifier assembly and speakers.

Fig 1: Identifying Stereo Component Amplifier Assembly And Speakers Connectors

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

TEXT IN ILLUSTRATION

*A	for 12 Speakers
*1	Front view of wire harness connector (to Stereo Component Amplifier Assembly)
*2	Front view of wire harness connector (to Rear No. 2 Speaker)
*3	Front view of wire harness connector (to Front No. 1 Speaker, Rear No. 1 Speaker)

Measure the resistance between the stereo component amplifier assembly and body ground to check for a short circuit in the wire harness.

Standard Resistance

Tester Connection	Condition	Specified Condition
O16-3 (WFL+) - Body ground	Always	10 kΩ or higher
O16-8 (WFL-) - Body ground	Always	10 kΩ or higher
O16-10 (WFR+) - Body ground	Always	10 kΩ or higher
O16-9 (WFR-) - Body ground	Always	10 kΩ or higher
O16-4 (RL+) - Body ground	Always	10 kΩ or higher
O16-11 (RL-) - Body ground	Always	10 kΩ or higher
O16-5 (RR+) - Body ground	Always	10 kΩ or higher
O16-12 (RR-) - Body ground	Always	10 kΩ or higher

for 12 Speakers:

Measure the resistance between each of the rear No. 2 speakers and body ground to check for a short circuit in the wire harness.

Standard Resistance

Tester Connection	Condition	Specified Condition
L1-3 (+) - Body ground	Always	10 kΩ or higher
L1-4 (-) - Body ground	Always	10 kΩ or higher
K1-3 (+) - Body ground	Always	10 kΩ or higher
K1-4 (-) - Body ground	Always	10 kΩ or higher

Measure the resistance between each of the front No. 1 speakers and the stereo component amplifier assembly to check for an open circuit in the wire harness.

Standard Resistance

Tester Connection	Condition	Specified Condition
O16-3 (WFL+) - J2-1	Always	Below 1 Ω
O16-8 (WFL-) - J2-2	Always	Below 1 Ω
O16-10 (WFR+) - I3-1	Always	Below 1 Ω
O16-9 (WFR-) - I3-2	Always	Below 1 Ω

for 9 Speakers:

Measure the resistance between each of the rear No. 1 speakers and the stereo component amplifier assembly to check for an open circuit in the wire harness.

Standard Resistance

Tester Connection	Condition	Specified Condition
O16-4 (RL+) - L4-1	Always	Below 1 Ω
O16-11 (RL-) - L4-2	Always	Below 1 Ω
O16-5 (RR+) - K4-1	Always	Below 1 Ω
O16-12 (RR-) - K4-2	Always	Below 1 Ω

for 12 Speakers:

Measure the resistance between each of the rear No. 2 speakers and the stereo component amplifier assembly to check for an open circuit in the wire harness.

Standard Resistance

Tester Connection	Condition	Specified Condition
O16-4 (RL+) - L1-1 (+TW)	Always	Below 1 Ω
O16-11 (RL-) - L1-2 (-TW)	Always	Below 1 Ω
O16-5 (RR+) - K1-1 (+TW)	Always	Below 1 Ω
O16-12 (RR-) - K1-2 (-TW)	Always	Below 1 Ω

for 12 Speakers:

Measure the resistance between each of the rear No. 2 speakers and the rear No. 1 speakers to check for an open circuit in the wire harness.

Standard Resistance

Tester Connection	Condition	Specified Condition
L1-3 (+) - L4-1	Always	Below 1 Ω
L1-4 (-) - L4-2	Always	Below 1 Ω
K1-3 (+) - K4-1	Always	Below 1 Ω
K1-4 (-) - K4-2	Always	Below 1 Ω

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: Go to next step

INSPECT FRONT NO. 1 SPEAKER

Resistance check

Fig 2: Measure The Resistance

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

Standard Resistance

Tester Connection	Condition	Specified Condition
J2-1 - J2-2	Always	3.2 to 4.8 Ω
I3-1 - I3-2	Always	3.2 to 4.8 Ω

TEXT IN ILLUSTRATION

*1	Component without harness connected (Front No. 1 Speaker)

NG → See step 13

OK: Go to next step

INSPECT FRONT NO. 4 SPEAKER

Resistance check

Fig 3: Measure The Resistance

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

Standard Resistance

Tester Connection	Condition	Specified Condition
H2-1 - H2-2	Always	4.8 to 7.2 Ω

TEXT IN ILLUSTRATION

*1	Component without harness connected (Front No. 4 Speaker)

NG → See step 16

OK: Go to next step

INSPECT REAR NO. 1 SPEAKER

Resistance check

Fig 4: Measure The Resistance

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

Standard Resistance

Tester Connection	Condition	Specified Condition
L4-1 - L4-2	Always	3.2 to 4.8 Ω
K4-1 - K4-2	Always	3.2 to 4.8 Ω

TEXT IN ILLUSTRATION

*1	Component without harness connected (Rear No. 1 Speaker)

Proceed to the next step based on the inspection result.

Result

Condition	Proceed to
OK (for 12 Speakers)	A
OK (for 9 Speakers)	B
NG	C

B → See step 17

C → See step 15

A: Go to next step

INSPECT REAR NO. 2 SPEAKER

Resistance check

Fig 5: Measure The Resistance

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

Standard Resistance

Tester Connection	Condition	Specified Condition
L1-1 (+TW) - L1-2 (-TW)	Always	10 kΩ or higher
K1-1 (+TW) - K1-2 (-TW)	Always	10 kΩ or higher

TEXT IN ILLUSTRATION

*1	Component without harness connected (Rear No. 2 Speaker)

NG → See step 20

OK → See step 17

CHECK HARNESS AND CONNECTOR

Disconnect the connectors shown in the illustration from the stereo component amplifier assembly, DCM (telematics transceiver)*1 and speakers.

*1: w/ Manual (SOS) Switch

Fig 6: Stereo Component Amplifier Assembly, DCM (Telematics Transceiver)*1 And Speakers Connectors (1 Of 2)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Fig 7: Stereo Component Amplifier Assembly, DCM (Telematics Transceiver)*1 And Speakers Connectors (2 Of 2)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

TEXT IN ILLUSTRATION

*A	for 9 Speakers
*B	for 12 Speakers
*C	for LH
*D	for RH
*E	w/ Manual (SOS) Switch
*1	Front view of wire harness connector (to Stereo Component Amplifier Assembly)
*2	Front view of wire harness connector (to Stereo Component Amplifier Assembly)
*3	Front view of wire harness connector (to Front No. 2 Speaker)
*4	Front view of wire harness connector (to Front No. 3 Speaker, Front No. 4 Speaker)
*5	Front view of wire harness connector (to Rear No. 3 Speaker)
*6	Front view of wire harness connector (to DCM (Telematics Transceiver))

Measure the resistance between the stereo component amplifier assembly and body ground to check for a short circuit in the wire harness.

Standard Resistance

FOR 12 SPEAKERS

Tester Connection	Condition	Specified Condition
O17-1 (WF1+) - Body ground	Always	10 kΩ or higher
O17-5 (WF1-) - Body ground	Always	10 kΩ or higher
O17-2 (WF2+) - Body ground	Always	10 kΩ or higher
O17-6 (WF2-) - Body ground	Always	10 kΩ or higher
O17-4 (FR+) - Body ground	Always	10 kΩ or higher
O17-10 (FR-) - Body ground	Always	10 kΩ or higher
O17-3 (FL+) - Body ground	Always	10 kΩ or higher
O17-9 (FL-) - Body ground	Always	10 kΩ or higher
O17-8 (CTR+) - Body ground	Always	10 kΩ or higher
O17-7 (CTR-) - Body ground	Always	10 kΩ or higher

FOR 9 SPEAKERS

Tester Connection	Condition	Specified Condition
O34-1 (FL+) - Body ground	Always	10 kΩ or higher
O34-5 (FL-) - Body ground	Always	10 kΩ or higher
O34-2 (FR+) - Body ground	Always	10 kΩ or higher
O34-6 (FR-) - Body ground	Always	10 kΩ or higher
O34-8 (CTR+) - Body ground	Always	10 kΩ or higher
O34-7 (CTR-) - Body ground	Always	10 kΩ or higher

Measure the resistance between each of the front No. 2 speakers and body ground to check for a short circuit in the wire harness.

Standard Resistance

Tester Connection	Condition	Specified Condition
I5-3 (+) - Body ground	Always	10 kΩ or higher
I5-4 (-) - Body ground	Always	10 kΩ or higher
J4-3 (+) - Body ground	Always	10 kΩ or higher
J4-4 (-) - Body ground	Always	10 kΩ or higher

w/ Manual (SOS) Switch:

Measure the resistance between the front No. 2 speaker RH and body ground to check for a short circuit in the wire harness.

Standard Resistance

Tester Connection	Condition	Specified Condition
I5-1 (TWR+) - Body ground	Always	10 kΩ or higher
I5-2 (TWR-) - Body ground	Always	10 kΩ or higher

Measure the resistance between the front No. 2 speaker LH and the stereo component amplifier assembly to check for an open circuit in the wire harness.

Standard Resistance

FOR 12 SPEAKERS

Tester Connection	Condition	Specified Condition
O17-3 (FL+) - J4-1 (TWL+)	Always	Below 1 Ω
O17-9 (FL-) - J4-2 (TWL-)	Always	Below 1 Ω

FOR 9 SPEAKERS

Tester Connection	Condition	Specified Condition
O34-1 (FL+) - J4-1 (TWL+)	Always	Below 1 Ω
O34-5 (FL-) - J4-2 (TWL-)	Always	Below 1 Ω

w/o Manual (SOS) Switch:

Measure the resistance between the front No. 2 speaker RH and the stereo component amplifier assembly to check for an open circuit in the wire harness.

Standard Resistance

FOR 12 SPEAKERS

Tester Connection	Condition	Specified Condition
O17-4 (FR+) - I5-1 (TWR+)	Always	Below 1 Ω
O17-10 (FR-) - I5-2 (TWR-)	Always	Below 1 Ω

FOR 9 SPEAKERS

Tester Connection	Condition	Specified Condition
O34-2 (FR+) - I5-1 (TWR+)	Always	Below 1 Ω
O34-6 (FR-) - I5-2 (TWR-)	Always	Below 1 Ω

w/ Manual (SOS) Switch:

Measure the resistance between the stereo component amplifier assembly and the DCM (telematics transceiver) to check for an open circuit in the wire harness.

Standard Resistance

FOR 12 SPEAKERS

Tester Connection	Condition	Specified Condition
O17-4 (FR+) - G25-2 (SPI+)	Always	Below 1 Ω
O17-10 (FR-) - G25-3 (SPI-)	Always	Below 1 Ω

FOR 9 SPEAKERS

Tester Connection	Condition	Specified Condition
O34-2 (FR+) - G25-2 (SPI+)	Always	Below 1 Ω
O34-6 (FR-) - G25-3 (SPI-)	Always	Below 1 Ω

w/ Manual (SOS) Switch:

Measure the resistance between the front No. 2 speaker RH and the DCM (telematics transceiver) to check for an open circuit in the wire harness.

Standard Resistance

Tester Connection	Condition	Specified Condition
G25-5 (SPO+) - I5-1 (TWR+)	Always	Below 1 Ω
G25-6 (SPO-) - I5-2 (TWR-)	Always	Below 1 Ω

Measure the resistance between the front No. 4 speaker and the stereo component amplifier assembly to check for an open circuit in the wire harness.

Standard Resistance

FOR 12 SPEAKERS

Tester Connection	Condition	Specified Condition
O17-8 (CTR+) - H2-2	Always	Below 1 Ω
O17-7 (CTR-) - H2-1	Always	Below 1 Ω

FOR 9 SPEAKERS

Tester Connection	Condition	Specified Condition
O34-8 (CTR+) - H2-2	Always	Below 1 Ω
O34-7 (CTR-) - H2-1	Always	Below 1 Ω

for 12 Speakers:

Measure the resistance between the rear No. 3 speaker and the stereo component amplifier assembly to check for an open circuit in the wire harness.

Standard Resistance

Tester Connection	Condition	Specified Condition
O17-1 (WF1+) - P22-1 (WF1+)	Always	Below 1 Ω
O17-5 (WF1-) - P22-3 (WF1-)	Always	Below 1 Ω
O17-2 (WF2+) - P22-2 (WF2+)	Always	Below 1 Ω
O17-6 (WF2-) - P22-4 (WF2-)	Always	Below 1 Ω

Measure the resistance between each of the front No. 2 speakers and the front No. 3 speakers to check for an open circuit in the wire harness.

Standard Resistance

Tester Connection	Condition	Specified Condition
I5-3 (+) - I6-2	Always	Below 1 Ω
I5-4 (-) - I6-1	Always	Below 1 Ω
J4-3 (+) - J6-2	Always	Below 1 Ω
J4-4 (-) - J6-1	Always	Below 1 Ω

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: Go to next step

INSPECT FRONT NO. 2 SPEAKER

Resistance check

Fig 8: Measure The Resistance

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

Standard Resistance

Tester Connection	Condition	Specified Condition
I5-1 (TWR+) - I5-2 (TWR-)	Always	10 kΩ or higher
J4-1 (TWL+) - J4-2 (TWL-)	Always	10 kΩ or higher

TEXT IN ILLUSTRATION

*A	for RH
*B	for LH
*1	Component without harness connected (Front No. 2 Speaker)

NG → See step 19

OK: Go to next step

INSPECT FRONT NO. 3 SPEAKER

Resistance check

Fig 9: Measure The Resistance

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

Standard Resistance

Tester Connection	Condition	Specified Condition
I6-1 - I6-2	Always	3.2 to 4.8 Ω
J6-1 - J6-2	Always	3.2 to 4.8 Ω

TEXT IN ILLUSTRATION

*1	Component without harness connected (Front No. 3 Speaker)

Proceed to the next step based on the inspection result.

Result

Condition	Proceed to
OK (for 12 Speakers)	A
OK (for 9 Speakers, w/ Manual (SOS) Switch)	B
OK (for 9 Speakers, w/o Manual (SOS) Switch)	C
NG	D

B → See step 12

C → See step 17

D → See step 14

A: Go to next step

INSPECT REAR NO. 3 SPEAKER

Resistance check

Fig 10: Measure The Resistance

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

Standard Resistance

Tester Connection	Condition	Specified Condition
P22-1 (WF1+) - P22-3 (WF1-)	Always	2.4 to 3.6 Ω
P22-2 (WF2+) - P22-4 (WF2-)	Always	2.4 to 3.6 Ω

TEXT IN ILLUSTRATION

*1	Component without harness connected (Rear No. 3 Speaker)

Proceed to the next step based on the inspection result.

Result

Condition	Proceed to
OK (w/ Manual (SOS) Switch)	A
OK (w/o Manual (SOS) Switch)	B
NG	C

B → See step 17

C → See step 18

A: Go to next step

INSPECT DCM (TELEMATICS TRANSCEIVER)

Resistance check

Fig 11: Measure The Resistance

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

Standard Resistance

Tester Connection	Condition	Specified Condition
G25-2 (SPI+) - G25-5 (SPO+)	Always	Below 1 Ω
G25-3 (SPI-) - G25-6 (SPO-)	Always	Below 1 Ω
G25-2 (SPI+) - G25-3 (SPI-)	Always	10 kΩ or higher
G25-5 (SPO+) - G25-6 (SPO-)	Always	10 kΩ or higher
G25-3 (SPI-) - Body ground	Always	10 kΩ or higher
G25-2 (SPI+) - Body ground	Always	10 kΩ or higher

TEXT IN ILLUSTRATION

*1	Component without harness connected (DCM (Telematics Transceiver))

NG → See step 21

OK → See step 17

REPLACE FRONT NO. 1 SPEAKER. Refer to REMOVAL
REPLACE FRONT NO. 3 SPEAKER. Refer to REMOVAL
REPLACE REAR NO. 1 SPEAKER. Refer to REMOVAL
REPLACE FRONT NO. 4 SPEAKER. Refer to REMOVAL
REPLACE STEREO COMPONENT AMPLIFIER ASSEMBLY. Refer to REMOVAL
REPLACE REAR NO. 3 SPEAKER. Refer to REMOVAL
REPLACE FRONT NO. 2 SPEAKER. Refer to REMOVAL
REPLACE REAR NO. 2 SPEAKER. Refer to REMOVAL
REPLACE DCM (TELEMATICS TRANSCEIVER). Refer to REMOVAL