2001 TOYOTA PRIUS Service Repair Manual

I15474
GR±B4 A7
A/C Amplifier C11
Combination MeterG1
Gateway ECU
B8
Body ECUE10
Engine Control Module
15MP2+
MPX+ GR4 11
3 2
MPX+MPX±
MPX+ MPX±
MPX2MPX1 GR±B
1613
GRGR±L11
14MPD1
MPD2
± DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
DI±775
2001 PRIUS (RM778U)
DTC B1261 / 61 ECM communication stop
CIRCUIT DESCRIPTION
This DTC is output when communication stops between ECM and body ECU.
DTC No.DTC Detecting ConditionTrouble Area
B1261/61N i ti f ECM th 10 d
ECMB1261/61No communication from ECM more than 10 seconds.
ECM

Wireharness
WIRING DIAGRAM
DI1SV±05

DI±776
± DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
1 Check ECM.
CHECK:
Check that the engine starts normally.
HINT:
With this inspection, ECM CPU can be diagnosed if it works normally or not.
NG Replace the ECM.
OK

I15537
Body ECU
MPX±
ECM
MPX1
Gateway
ECU
MPX1 MPX2
± DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
DI±777
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 (1) and (2), or either
(1) or (2).
HINT:
If there is OPEN in wireharness of either (1) or (2), please repair
it.
NG Repair or replace wireharness.
OK
Replace the ECM.

I15474
GR±B4 A7
A/C Amplifier C11
Combination MeterG1
Gateway ECU
B8
Body ECUE11
Engine Control Module
15MP2+
MPX+ GR4 11
3 2
MPX+MPX±
MPX1 MPX±
MPX2MPX1 GR±B
1613
GRGR±L11 14
± DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
DI±779
2001 PRIUS (RM778U)
DTC B1266 / 66 Instrument panel system communica-
tion bus malfunction (+B short)
DTC B1267 / 67 Instrument panel system communica-
tion bus malfunction (GND short)
CIRCUIT DESCRIPTION
This DTC is output when +B or GND short occurs on instrument panel system communication bus. If +B or
GND short is detected on instrument panel system communication bus, separate it by bus cut relay in body
ECU to prevent while communication buses' failure.
WIRING DIAGRAM
DI7O3±01

I15546
ECM
E11
I15545
Gateway
ECU
G1
DI±780
± DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
HINT:
On the system structure point of view, this DTC cannot display meter. In case of checking DTC, please use
hand±held tester.
1 Check the communication circuit inside ECM.
PREPARATION:
Disconnect the connector ºE11º of ECM.
CHECK:
Check the DTC.
OK:
Code B1266 or B1267 is not output
OK Replace the ECM.
NG
2 Check the communication circuit inside gateway ECU.
PREPARATION:
(a) Connect the connector ºE11º of ECM.
(b) Disconnect the connector ºG1º of gateway ECU.
CHECK:
Check the DTC.
OK:
Code B1266 or B1267 is not output
OK Replace the gateway ECU.
NG

I15544
A/C
Amplifier
A7
I15543
Combination
Meter
C11
± DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
DI±781
2001 PRIUS (RM778U)
3 Check the communication circuit inside A/C amplifier.
PREPARATION:
(a) Connect the connector of ºG1º of gateway ECU.
(b) Disconnect the connector ºA7º of A/C amplifier.
CHECK:
Check the DTC.
OK:
Code B1266 or B1267 is not output
OK Replace the A/C amplifier.
NG
4 Check the communication circuit inside combination meter ECU.
PREPARATION:
(a) Connect the connector ºA7º of A/C amplifier.
(b) Disconnect the connector ºC11º of combination meter
ECU.
CHECK:
Check the DTC.
OK:
Code B1266 or B1267 is not output
OK Replace the combination meter ECU.
NG