2001 TOYOTA PRIUS Service Repair Manual

DI±666
± DIAGNOSTICSCRUISE CONTROL SYSTEM
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
1 Check combination meter (See page BE±2).
NG Replace combination meter.
OK
Check and replace hybrid vehicle control
ECU (See page DI±174).

DI7XP±01
± DIAGNOSTICSCOMBINATION METER SYSTEM
DI±669
2001 PRIUS (RM778U)
PRE±CHECK
1. BEFORE CHECK
Since a trouble symptom may result from multiple causes, check not only the part where a user complains
of but also the following items in order to be sure no other trouble is identified.

Fuse related parts

Wire harness related parts

Valve related parts
NOTICE:

Setting the ignition switch to START temporarily stops all meter operation, however, this is not
an error.

When replacing the combination meter ECU, carefully avoid any contact with the IC.

Removing a battery terminal during engine operation may cause a reversed current and lead
to malfunction.

When disconnecting any connector or terminal, be sure to disconnect the battery terminal.

Flashing pattern No.1
Flashing pattern No.2
0.6 sec. 0.6 sec.
0.3 sec. 0.3 sec. 1.2 sec. ON
OFF ON
OFF
0.3 sec.
DI±670
± DIAGNOSTICSCOMBINATION METER SYSTEM
2001 PRIUS (RM778U)
2. FUEL GAUGE DIAGNOSIS CHECK
(a) Fuel emergency display
HINT:
If FR voltage input to the fuel sender gauge is abnormal (4.8 V or more, or 0.06 V or less) due to any error,
an emergency will be displayed.
(b) Display:
Immediately after the ignition switch is ON, all of the segments flash.
Diagnosis displayTrouble ItemPlausible Cause
All segments flashing
(Flashing pattern No. 1)
Cycle: 1.2 sec
Duty: 50 %Multiple communication errorCommunication is cut off.
4. Body ECU faulty
5. Engine ECU faulty
6. Open or short in wire harness for communica-
tion
HINT:
Referring to the attached reference material 1 or
2, specify the main cause
All segments flashing
(Flashing pattern No. 2)
(300 msec. ON, 300 msec OFF) x 2 + 1.2
sec. OFFSender gauge related trouble1. Sender gauge faulty
2. Open or short in wire harness
Display segments and ºEº flashing.
(Flashing pattern No. 1)
Cycle: 1.2 sec
Duty: 50 %Temperature sensor (located in the tank) related
trouble1. Temperature sensor faulty
2. Open or short in wire harness
Display segments and ºEº flashing.
(Flashing pattern No. 2)
(300 msec. ON, 300 msec. OFF) x 2 + 1.2
sec. OFFIndication sensor (located in the meter ) trouble1. Combination meter faulty
Segment No. 1 flashing
(Flashing pattern No. 1)
Cycle: 1.2 sec
Duty: 50 %This does not mean any failure.
When a battery is connected, it continues flash-
ing until the volume is confirmed.This occurs when the battery is turned ON.
HINT:
Low fuel warning: Cycle: 0.6 sec.;
Duty: 50 %

DI7XR±01
I17803
Connector ºAº Connector ºBº
(LHD model) COMBINATION METER DI±672
± DIAGNOSTICSCOMBINATION METER SYSTEM
2001 PRIUS (RM778U)
TERMINALS OF ECU
Disconnect connector ºAº and ºBº from the combination meter and inspect the connectors on the wire har-
ness side as shown in the table.
Tester connectionConditionSpecified condition
A1 ± Ground
(ILL ± Body ground)Ignition switch ON and tail cancel switch ON or
OFFBelow 1V or 4.5 ± 5.5 V
A2 ± Ground
(E ± Body ground)ConstantContinuity
A3 ± Ground
(OPO ± Body ground)Ignition switch ON and trip reset switch ON or
OFFBelow 1V or 4.5 ± 5.5 V
A9 ± Ground
(SI ± Body ground)Ignition switch ON and slowly turn drive wheelBelow 1V or 10 ± 14 V
A10 ± Ground
(LP ± Body ground)Ignition switch ON and ABS indicator ON or OFFBelow 1V or 10 ± 14 V
A11 ± Ground
(L ± Body ground)Ignition switch ONPulse generation
A13 ± GroundI iti it h ON d l l t d i h lBelow 1V or 10 ± 14 VA13 Ground
(+S ± Body ground)Ignition switch ON and slowly turn drive wheelBelow 1V or 4.5 ± 5.5 V
A14 ± Ground
(ES ± Body ground)ConstantContinuity
A15 ± Ground
(EP ± Body ground)ConstantContinuity
A16 ± Ground
(SW ± Body ground)Ignition switch ON and air bag indicator light ON
or OFFBelow 1V or 10 ± 14 V
A17 ± Ground
(S ± Body ground)Headlight dimmer switch Hi or LowBelow 1V or 10 ± 14 V
A18 ± Ground
(B ± Body ground)Ignition switch ON and turn signal switch rightBelow 1V or 10 ± 14 V
A19 ± Ground
(B ± Body ground)Ignition switch ON and turn signal switch leftBelow 1V or 10 ± 14 V
A21 ± Ground
(B ± Body ground)Constant10 ± 14 V
A22 ± Ground
(IG ± Body ground)Ignition switch OFF or ONBelow 1V or 10 ± 14 V

± DIAGNOSTICSCOMBINATION METER SYSTEM
DI±673
2001 PRIUS (RM778U) B1 ± Ground
(ROUT ± Body ground)
Ignition switch ON and shift lever position is ºRº
or except ºRºBelow 1V or 10 ± 14 V
B2 ± Ground
(MPX+ ± Body ground)Ignition switch ONPulse generation
B3 ± Ground
(MPX ± Body ground)Ignition switch ONPulse generation
B5 ± Ground
(ACC ± Body ground)Ignition switch ACC10 ± 14 V

DI7XS±01
DI±674
± DIAGNOSTICSCOMBINATION METER SYSTEM
2001 PRIUS (RM778U)
PROBLEM SYMPTOMS TABLE
TROUBLESHOOTING:
Flow chart No.SymptomSee page
1Check the communication between the combination meter and the multiplex com-
munication circuit.DI±671
2The whole meter does not functionDI±672
3The margin of error in speedometer is large. Or it remains as 0 mph.DI±673
4Fuel receiver gauge is inoperative or improper.DI±674
5Indicators or warning lights do not light up.DI±676
Fuel gauge:
SymptomSuspect AreaSee page
Displayed level is higher or lower than the actual level.1. Inclination sensor resetting
2. Body ECUBE±47
IN±41
General:
SymptomSuspect area
Meter display does not properly function.3. Combination meter ECU
Entirely black screen appears.1. Fuse
2. Wire harness and connector
3. Combination meter ECU
Turning the light control switch ON does not dim the light.1. Illumination switch
2. Wire harness and connector
3. Combination meter ECU
Brightness cannot be changed by the illumination switch operation.1. Illumination switch
2. Wire harness and connector
3. Combination meter ECU
Speedometer:
SymptomSuspect area
Improper display (Remained as 0 km/h)1. Accessory that utilizes vehicle speed signals
2. Brake ECU
3. Combination meter ECU
4. Wire harness and connector
Speedometer only does not light up.1. Combination meter ECU
Abnormal display (Incomplete numbers displayed)1. Combination meter ECU
DIsplayed value changes frequently or sharply.1. Accessory that utilizes vehicle speed signals
2. Brake ECU
3. Combination meter ECU
4. Wire harness and connector
Margin of error in speedometer is large.1. Accessory that utilizes vehicle speed signals
2. Brake ECU
3. Combination meter ECU
4. Wire harness and connector
ODO/TRIP Meter:
SymptomSuspect area
ODO/TRIP only does not light up.1. Combination meter ECU
Abnormal display (Incomplete number displayed)1. Combination meter ECU
Both meters do not integrate values. (When speedometer is normal)1. Combination meter ECU
Trip meter only does not integrate values.1. ODO/TRIP switch
2. Combination meter ECU