TOYOTA PRIUS 2001 Service Repair Manual

I15542
Body ECU
B8
I15542I15546I18344
Body ECU
B8
E11
DI±782
± DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
2001 PRIUS (RM778U)
5 Check for short circuit between combination meter ECU and body ECU.
PREPARATION:
Disconnect the connector ºB8º of body ECU.
CHECK:
Check the DTC.
OK:
Code B1266 or B1267 is not output
OK Repair or replace the wireharness between
combination meter ECU and body ECU.
NG
6 Check for short circuit between body ECU and ECM.
PREPARATION:
Connect the connector ºB8º of body ECU.
Disconnect the connector ºE11º of ECM.
CHECK:
Check the DTC.
OK:
Code B1266 or B1267 is not output
OK Repair or replace the wireharness between
body ECU and ECM.
NG

I15545
Gateway
ECU
G1
I15544
A/C
Amplifier
A7
± DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
DI±783
2001 PRIUS (RM778U)
7 Check for short circuit between ECM and gateway ECU.
PREPARATION:
Connect the connector ºB8º of body ECU.
Disconnect the connector ºG1º of gateway ECU.
CHECK:
Check the DTC.
OK:
Code B1266 or B1267 is not output
OK Repair or replace the wireharness between
ECM and gateway ECU.
NG
8 Check for short circuit between gateway ECU and A/C amplifier.
PREPARATION:
Connect the connector ºE11º of ECM.
Disconnect the connector ºA7º of A/C amplifier.
CHECK:
Check the DTC.
OK:
Code B1266 or B1267 is not output
OK Repair or replace the wireharness between
ECM and A/C amplifier.
NG

I15543
Combination
Meter
C11
DI±784
± DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
2001 PRIUS (RM778U)
9 Check for short circuit between A/C amplifier and combination meter ECU.
PREPARATION:
Connect the connector ºA7º of A/C amplifier.
Disconnect the connector ºC11º of combination meter ECU.
CHECK:
Check the DTC.
OK:
Code B1266 or B1267 is not output
OK Repair or replace the wireharness between A/C
amplifier and combination meter ECU.
NG
Replace the body ECU.

± DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
DI±785
2001 PRIUS (RM778U)
DTC B1271 / 71 Combination meter ECU communica-
tion stop
CIRCUIT DESCRIPTION
This DTC is output when communication stops between combination meter ECU and body ECU.
DTC No.DTC Detecting ConditionTrouble Area
B1271/71No communication from Combination meter ECU more than 10
Combination meter ECUB1271/71No communication from Combination meter ECU more than 10
seconds.

Combination meter ECU

Wireharness
WIRING DIAGRAM
See page DI±770
INSPECTION PROCEDURE
1 Check combination meter ECU.
CHECK:
Start the engine and check that the speed meter and tacometer operate normally.
HINT:
With this inspection, the combination meter ECU CPU can be diagnosed if it works normally or not.
NG Replace the combination meter ECU.
OK
DI1SY±03

I15539
Combination Meter A/C amplifier
ºC6º
MPX1MPX+ Combination
Meter Body ECU
MPX+
MPX±
DI±786
± DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
2001 PRIUS (RM778U)
2 Check wireharness
PREPARATION:
Disconnect connector ºA7º of A/C amplifier, ºC11º of combina-
tion meter ECU and ºB8º of body ECU.
CHECK:
(a) Check continuity between terminals MPX+ of A/C amplifi-
er and MPX± of combination meter ECU.
(b) Check continuity between terminals MPX+ of combina-
tion meter ECU and MPX1 of body ECU.
OK:
There is a continuity in wireharness of both (a) and (b), or either
(a) or (b).
HINT:
If there is OPEN in wireharness of either (a) or (b), please repair
it.
NG Repair or replace wireharness.
OK
Replace the combination meter ECU.

± DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
DI±787
2001 PRIUS (RM778U)
DTC B1274/74 Multi display communication stop
CIRCUIT DESCRIPTION
This DTC is output when communication stops between multi display and body ECU.
DTC No.DTC Detecting ConditionTrouble Area
B1274/74N i ti f lti di l th 10 d
Multi displayB1274/74No communication from multi display more than 10 seconds.
Multi dis lay

Wireharness
WIRING DIAGRAM
See Page DI±770
DI1SY±04

I15538
Multi Display
Gateway ECU TX3+
GTX+
GTX± TX3±
DI±788
± DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
1 Check multi display ECU.
CHECK:
Check that the multi display operate normally.
HINT:
With this inspection, the multi display CPU can be diagnosed if it works normally or not.
NG Replace the multi display.
OK
2 Check wireharness.
PREPARATION:
Disconnect connector ºM2º of multi display and ºG1º of gateway
ECU.
CHECK:
(a) Check continuity between terminals TX3+ of multi display
and GTX+ of gateway ECU.
(b) Check continuity between terminals TX3± of multi display
and GTX± of gateway ECU.
OK:
There is a continuity in wireharness.
HINT:
If there is OPEN in wireharness, please repair it.
NG Repair or replace wireharness.
OK
Replace the multi display.

± DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
DI±789
2001 PRIUS (RM778U)
DTC B1293/93 Gateway ECU communication stop
CIRCUIT DESCRIPTION
This DTC is output when communication stops between gateway ECU and body ECU.
DTC No.DTC Detecting ConditionTrouble Area
B1293/93N i ti f t ECU th 10 d
Gateway ECUB1293/93No communication from gateway ECU more than 10 seconds.
Gateway ECU

Wireharness
WIRING DIAGRAM
See page DI±770
INSPECTION PROCEDURE
1 Check open door warning light.
CHECK:
Connection that the gateway ECU and BEAN (Body Electrical Area Network) can be checked by DTC trans-
mitted by the body ECU.
See ºINSPECT OPEN DOOR INDICATOR LIGHT on page DI±752.
NG Replace the gateway ECU.
OK
DI1SY±05

I15537MPX1 MPX±Body ECU
ECM
Gateway ECU
MPX1 MPX2
DI±790
± DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
2001 PRIUS (RM778U)
2 Check wireharness
PREPARATION:
Disconnect connector ºB8º of body ECU, ºE11º of ECM and
ºG1º of gateway ECU.
CHECK:
(a) Check continuity between terminals MPX± of body ECU
and MPX2 of ECM.
(b) Check continuity between terminals MPX1 of ECM and
MPX1 of gateway ECU.
OK:
There is a continuity in wireharness of both (a) and (b), or either
(a) or (b).
HINT:
If there is OPEN in wireharness of either (a) or (b), please repair
it.
NG Repair or replace wireharness.
OK
Replace the gateway ECU.

± DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
DI±791
2001 PRIUS (RM778U)
Power Source Circuit
CIRCUIT DESCRIPTION
This circuit provides power to operate the gateway ECU.
DI7O4±01