TOYOTA PRIUS 2001 Service Repair Manual

I03343I03344I03345I03977
ECU
ECU
ECU
ECU
ECU
ECU OpenOpen
ECU
ECU
Open
ECU Disconnection (DTC is detected)
Open (DTC is detected)
Open (DTC is not detected)
I03346
Body ECU
OpenOpen
Detect the DTC of commu-
nication stop of the 3 ECUs. Example
DI±758
± DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
2001 PRIUS (RM778U)
(b) If DTC of ECU communication stop is output, there is a
possibility of connector disconnection or 2 communica-
tion buses open. It will not become abnormal with only 1
communication bus open.
(c) If 2 communication buses are open at the position as
shown in the illustration, DTC of ECU communication stop
between those 2 buses is output.

± DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
DI±759
2001 PRIUS (RM778U)
2. BASIC INSPECTION
INSPECT BODY ECU
1 Check room light operation.
HINT:
With this inspection body ECU CPU can be diagnosed if it works normal or not.
CHECK:
Check if the room light works normal at DOOR position.
OK Go to next stepºOPEN DOOR INDICATOR LIGHT
INSPECTIONº.
NG
2 Check interior light system (Except body ECU) (See page BE±27).
OK Replace the body ECU.
NG
Repair of replace malfunction part.

I15594
A04550
Tc CG
DLC3
DI±760
± DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
2001 PRIUS (RM778U)
INSPECT OPEN DOOR INDICATOR LIGHT
1 Check open door indicator light.
CHECK:
Check if open door Indicator light is turned on when either door
open.
HINT:
If open door Indicator light is not turned on, DTC will not be out-
put.
OK Go to step 3. ºDTC CHECKº.
NG
Repair the open door indicator light (See
page BE±39).
3. DTC CHECK (Using diagnosis check wire)
(a) Using SST, connect terminals Tc and CG of DLC3.
SST 09843±18020
(b) Turn the ignition switch ON.
(c) Read the DTC on the open door indicator light.

N13628
Malfunction Code 12
Malfunction Code 11 and 12
0.25 sec.
0.25 sec.
1.5 sec.
Normal Code
4.5 sec.
0.5 sec. 0.5 sec.
2.5 sec. 4.5 sec.
F12396
DLC3
± DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
DI±761
2001 PRIUS (RM778U)
As an example, the blinking patterns for codes; normal, 12, and
11 and 12 are shown in the illustration.
(d) Check for the problem using the DTC table on the next
page.
(e) After completing the check, turn the ignition switch off,
and disconnect terminals Tc and E1.
4. DTC CHECK (Using hand±held tester)
(a) Prepare the hand±held tester.
(b) Connect the hand±held tester to DLC3.
(c) Turn the ignition switch ON and switch the hand±held tes-
ter main switch ON.
(d) Use the hand±held tester to check the DTCs, note them
down. (For opening instructions, see the hand±held tes-
ter 's instruction book.)
(e) See page DI±757 to confirm the details of the DTCs.
5. DTC CLEARANCE
DTC will be cleared when the trouble output to DTC is recov-
ered normally.

DI7O1±01
I15530
BODY ECU
MPX2MPX1
B8B9
I15529
DRIVER DOOR ECU
P8
MPX1
I15592
ECM
MPX1MPX2
E11E10E9E8
DI±764
± DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
2001 PRIUS (RM778U)
TERMINALS OF ECU

I15590
A/C amplifier
MPX+ MP2+
A9A8A7
I15589
Combination Meter ECU
C10
C11MPX+
MPX±
I15528
Multi Display
TX3+
M2
M4M3
TX1+
TX1±
TX3±
± DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
DI±765
2001 PRIUS (RM778U)
L

I17261
Gateway ECU
G1
GTX+MPD1
GTX±
MPD2
DI±766
± DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
2001 PRIUS (RM778U)Symbols (Terminals No.)
Wiring ColorConditionSTD Value (V)
IG e GNDBYWBIgnition switch OFF or ACCBelow 1 VIG e GND
(2 e 14)B±Y e W±BIgnition switch ON10 ± 14 V
MDP1 (4)GR±BA/C ECU communication circuit±
GTX+ (5)RAVC±LAN communication circuit±
CG e Body ground
(7 e Body ground)W±B e
Body groundConstantBelow 1 V
BATT e GND
(8 e 14)R±G e W±BConstant10 ± 14 V
ACC e GNDGR RWBIgnition switch OFFBelow 1 VACC e GND
(9 e 14)GR±R e W±BIgnition switch ACC or ON10 ± 14 V
MDP2 (11)GR±LEngine and ECT ECU communication circuit±
GTX± (12)GAVC±LAN communication circuit±
GND e Body ground
(14 e Body ground)W±B e
Body groundConstantBelow 1 V

DI1SJ±03
I15494
Body ECU P9
Power Window
Master SW
18
RX 6
B8
Y
Y5
IG1 MPX1
± DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
DI±767
2001 PRIUS (RM778U)
CIRCUIT INSPECTION
DTC B1211 / 11 Driver door ECU communication stop
CIRCUIT DESCRIPTION
This DTC is output when communication stops between driver door ECU and body ECU.
DTC No.DTC Detecting ConditionTrouble Area
B1211/11No communication from driver door ECU more than 10 se-
Driver door ECUB1211/11No communication from driver door ECU more than 10 se
conds.

Driver door ECU

Wireharness
WIRING DIAGRAM

DI±768
± DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
1 Check driver door ECU.
CHECK:
Check if the driver door window glass auto up.
HINT:
With this inspection, the driver door ECU CPU can be diagnosed if it works normally or not.
NG Replace the driver door ECU.
OK

I15549
Body ECU
RX
MPX1 Driver
Door
ECU
± DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
DI±769
2001 PRIUS (RM778U)
2 Check wireharness.
PREPARATION:
Disconnect connector ºB8º of body ECU and ºP9º of driver door
ECU.
CHECK:
Check continuity between terminal RX of body ECU and MPX1
of driver door 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 driver door ECU.