TOYOTA SUPRA 1995 Service Repair Manual

INSPECTION PROCEDURE
(See page BE±123).
(See page IN±30).
Check door key lock and unlock switch.
(1)Remove the door trim and service hole cover.
(2)Disconnect the door key lock and unlock switch
connector.
Check continuity between terminals 1, 2 and 3 of
door key lock and unlock switch connector, when
door key lock and unlock switch is turned to the lock
side, unlock side and not turned.
Switch position
Lock side
Unlock side
Terminal
Replace door key lock and unlock switch.
OFF
Proceed to next circuit inspection shown on
matrix chart (See page
BE±123).
Repair or replace harness or connector.
Check harness and connectors between ECU and switch, switch and body
ground (See page IN±30).
± BODY ELECTRICAL SYSTEMBE±159THEFT DETERRENT AND DOOR LOCK CONTROL SYSTEM

Key Unlock Warning Switch Circuit
CIRCUIT DESCRIPTION
The key unlock warning switch goes on when the ignition key is inserted in the key cylinder and goes off when
the ignition key is removed.
The ECU operates the key confinement prevention function while the key unlock warning switch is on.
BE±160± BODY ELECTRICAL SYSTEM
THEFT DETERRENT AND DOOR LOCK CONTROL SYSTEM

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INSPECTION PROCEDURE
(See page IN±30).
Check key unlock warning switch.
Check continuity between terminals 1 and 2 of key
unlock warning switch connector, when the key is
inserted to the key cylinder or removed.
Switch position
Terminal
Replace key unlock warning switch.
OFF (Key inserted)
Proceed to next circuit inspection shown on
matrix chart (See page
BE±123).
Repair or replace harness or connector.
Check harness and connectors between ECU and key unlock warning
switch, key unlock warning switch and body ground (See page IN±30).
Disconnect key unlock warning switch connector.
ON (Key inserted)
± BODY ELECTRICAL SYSTEMBE±161THEFT DETERRENT AND DOOR LOCK CONTROL SYSTEM

CRUISE CONTROL SYSTEM
PARTS LOCATION
BE±162± BODY ELECTRICAL SYSTEM
CRUISE CONTROL SYSTEM

HOW TO PROCEED WITH TROUBLESHOOTING
Perform troubleshooting in accordance with the procedure on the following page.
P. BE±164
P. BE±166 ~ BE±167
P. BE±24
P. BE±168P. BE±170
P. BE±165 ~ BE±167
P. BE±171 ~ BE±200
Vehicle brought to
Workshop
Customer Problem Analysis
Check and Clear Diagnostic Trouble
Codes (Precheck)
Symptom Simulation
Symptom does
not occur
Problem Symptom Confirmation
Diagnostic Code Check
Diagnostic Code Chart
Normal code
Malfunction Code
Matrix Chart of Problem Symptoms
Circuit Inspection
Input Signal
Check
Parts Inspection
Identification of Problem
Repair
Confirmation TestEND
Symptom
occurTitles inside are titles of pages in this manual,
with the page number indicated in the bottom por-
tion. See the indicated pages for detailed explana-
tions.
Step [2], [5], [8], [10]: Diagnostic steps permitting the use of
the TOYOTA hand±held tester or TOYOTA break±out±box.
± BODY ELECTRICAL SYSTEMBE±163CRUISE CONTROL SYSTEM

CUSTOMER PROBLEM ANALYSIS
 
 CRUISE CONTROL Check Sheet
Inspector 's
Name:
   Registration No. 
 Customer 's Name  Registration Year // 
 
 
 
 
 Frame No.
 
 
 
 
Date Vehicle
Brought In 
 // 
 Odometer Reading 
 
km
Miles
 Date Problem First Occurred //
 
 How Often does Problem Occur?
 
  Continuous Intermittent ( Times a day)
 
Vehicle Speed when Problem Occurred
 km/h
mph Vehicle Speed when Problem Occurred mph
 
 
 
 
 
 
 
 
Auto cancel occurs 
 
 
 
 Driving condition
City driving Freeway Up hill Down hill
 After cancel occurred, did the driver activate cruise
control again?
Yes No 
 
 
 
 
 
Cancel does not occur 
 
 
With brake ON With parking brake ON
EXCEPT D RANGE At 40 km/h (25 mph) or less
When control SW turns to CANCEL position
 
 
 
 
Symptoms 
 
 
 
Cruise control
malfunction 
 
 
 
Slip to acceleration side
Slip to acceleration side
 Hunting occurs
O/D cut off does not occur
O/D does not return
  Switch malfunction  SET  ACCEL.  COAST  RESUME  CANCEL 
 
 
  Faulty CRUISE MAIN
indicator light 
  Remains ON Does not light up Blinking
 Diagnostic Trouble 1st Time  Normal Code Malfunction Code (Code ) 
 Code Check 
 2nd Time
 
  Normal Code Malfunction Code (Code )
BE±164± BODY ELECTRICAL SYSTEM
CRUISE CONTROL SYSTEM

DIAGNOSIS SYSTEM
INDICATOR CHECK
1. Turn the ignition switch to ON.
2. Check that the CRUISE MAIN indicator light comes on when
the cruise control main switch is turned ON, and that the
indicator light goes off when the main switch is turned OFF.
HINT: If the indicator check result is not normal, proceed to
troubleshooting (See page BE±43 for the combination meter
section.)
DIAGNOSTIC TROUBLE CODE CHECK
HINT: If a malfunction occurs in the vehicle speed sensors or
actuator, etc. during cruise control driving, the ECU actuates
AUTO CANCEL of the cruise control and blinks the CRUISE
MAIN indicator light to inform the driver of a malfunction. At
the same time, the malfunction is stored in memory as a diag-
nostic trouble code.
OUTPUT OF DIAGNOSTIC TROUBLE CODE
Using diagnosis check wire:
1. Turn the ignition switch ON.
2. Using SST, connect terminals Tc and E
1 of DLC2.
SST 09843±18020
3. Read the diagnostic trouble code on the CRUISE MAIN
indicator light.
HINT: If the diagnostic trouble code is not output, inspect the
diagnosis circuit (See page BE±199).
As an example, the blinking patterns for codes; normal, 11
and 21 are shown in the illustration.
4. Check for the problem using the diagnostic trouble code table
on the next page.
5. After completing the check, disconnect terminals Tc and E
1,
and turn off the display.
± BODY ELECTRICAL SYSTEMBE±165CRUISE CONTROL SYSTEM

Using TOYOTA hand±held tester:
1. Hook up the TOYOTA hand±held tester to the DLC2.
2. Monitor the ECU data by following the prompts on the tester
screen.
HINT: TOYOTA hand±held tester has a ºSnapshotº function
which records the monitored data.
Please refer to the TOYOTA hand±held tester operator's
manual for further details.
ECU TERMINAL VALUES
MEASUREMENT USING TOYOTA
BREAK±OUT±BOX AND TOYOTA
HAND±HELD TESTER
1. Hook up the TOYOTA break±out±box and TOYOTA
handheld tester to the vehicle.
2. Read the ECU input/output values by following the prompts
on the hand±held tester screen.
HINT: TOYOTA hand±held tester has a ºSnapshotº function.
This records the measured values and is effective in the diag-
nosis of intermittent problems.
Please refer to the TOYOTA hand±held tester/TOYOTA
break±out±box operator's manual for further details. BE±166
± BODY ELECTRICAL SYSTEMCRUISE CONTROL SYSTEM

DIAGNOSTIC TROUBLE CODE
Source voltage drop.
Duty ratio of 100% output to motor
acceleration side.
Voltage abnormality in control switch.
Short in control switch circuit.
Vehicle Speed Sensor Pulse is abnormal.
Actual vehicle speed has dropped by 16 km/h
(10 mph) or more below the set speed.
Speed signal is not input to the ECU while cruise control is set.
Open in actuator motor circuit.
Position sensor detects abnormal voltage.
Position sensor signal value does not change when themotor operates.
Open in magnet clutch circuit for 0.8 sec.
Overcurrent (short) in magnet clutch circuit.
Overcurrent (short) in motor circuit.
Normal
DiagnosisLight Blinking Pattern
CRUISE MAIN IndicatorDTC
HINT: When 2 or more codes are indicated, the lowest numbered code will be displayed first.
(*) When the vehicle speed is reduced on uphill roads, the speed can be set again and driving continued.
(This is not a malfunction.)
± BODY ELECTRICAL SYSTEMBE±167CRUISE CONTROL SYSTEM

Diagnostic Trouble Code Clearance
1. After completing repairs the diagnostic trouble code retained
in memory can be cleared by removing the ECU±B fuse for
10 seconds or more, with the ignition switch off.
2. Check that the normal code is displayed after connecting the
fuse.
DIAGNOSTIC TROUBLE CODE CHART
If a malfunction code is displayed during the diagnostic trouble code check, check the circuit listed for that code
in the table below and proceed to the appropriate page.
 
 Code No.
 
 Circuit Inspection
 
 Page
 
 11, 14
 
  Actuator Motor Circuit.
 
 BE±171
 
 12
 
  Actuator Magnet Clutch Circuit.
 
 BE±172
 
 
 
13
 
 
 
 Actuator Motor Circuit
 Actuator Position Sensor Circuit
 
 
 
BE±171
BE±175
 
 
 
14
 
 
 
 Actuator Motor Circuit
 Actuator Position Sensor Circuit
 
 
 
BE±171
BE±175
 
 21
 
  Speed Sensor Circuit
 
 BE±177
 
 23
 
  Speed Sensor Circuit
 
 BE±177
 
 32, 34 
  Control Switch Circuit. (Cruise Control Switch) 
 BE±197
HINT:
1. If the instruction ºProceed to next circuit inspection shown on matrix chartº is given in the flow chart for
each circuit, proceed to the circuit with the next highest number in the table to continue check.
2. If the trouble still reappears even though there are no abnormalities in any of the other circuits, then check
or replace the cruise control ECU as the last step. BE±168
± BODY ELECTRICAL SYSTEM
CRUISE CONTROL SYSTEM