REPAIR MANUAL FOR CHASSIS & BODY

TOYOTASUPRA

Diagnosis System

OUTPUT OF DIAGNOSTIC CODES

1. Indicate Type A Code

1. Turn the ignition switch on.
2. Push the set/coast switch on, and keep it on.
3. Push the main switch on.
4. Meet the conditions listed below
5. Read the diagnosis code on the main switch indicator

No	Condition	Indication Code	Diagnosis
1	Set/Coast switch on		Set/Coast switch circuit is normal
2	Accel/Resume switch on		Accel/Resume switch circuit is normal
3	Vacuum switch on		Vacuum switch circuit is normal
4	Each cancel switch on (Stop light switch, Parking brake switch, Clutch switch, Neutral start switch, Cancel switch)		Each cancel switch circuit is normal
5	Drive 40km/h (25mph) or over		Speed sensor circuit is normal
6	Drive 40 km/h (25 mph) or below		Speed sensor circuit is normal

• Checking of No.4 code is done with the rear jacked up and engine idling.
• If there is no indication code, perform diagnosis and inspection

2. Indicate Type B Code

1. Do not turn the ignition switch and main switch off.
2. Push the set/coast switch on three times within two seconds.
3. Read the diagnosis code on the main switch indicator

No	Indication Code	Diagnosis
1		Actuator circuit is normal
2		Actuator circuit is abnormal
3		Speed sensor signal circuit is abnormal
4		Speed sensor signal circuit is abnormal
5		Accel/resume switch circuit is abnormal

• Indication codes appear with priority from No.11,
• Indication is stopped when vehicle speed is over 16km/h (10mph) or main switch is turned off.
• If there is no indication code, perform diagnosis and inspection

+------------------------+
|Turn ignition switch on.|
+----------+-------------+
           |
           |
+----------+-----------+        +--------------------+        +-----------------------------------+
|Is ECU-IG fuse normal?|-->NO-->|  Replace fuse,     |-->NO-->|* Short circuit in wire harness and|
+----------+-----------+        |Is operation normal?|        |  terminal 2 of the main switch    |
           |                    +---------+----------+        |* Inspect main switch              |
           |                              |                   +-----------------------------------+
           |                             Yes
          Yes                             |
           |                        +-----+-----+
           |                        |Fuse Faulty|
           |                        +-----------+
MAIN S/W   |
           |
+----------+--------------------------------+        +------------------------------------------+
|INSPECT POWER SOURCE                       |        |* Open circuit in wire harness between    |
|Is there battery voltage between terminal 2|-->NO-->|  ECU-IG fuse and terminal 2 of main      |
|and body ground?                           |        |  switch                                  |
+----------+--------------------------------+        +------------------------------------------+
           |
          Yes
           |
+----------+--------------------------------+        +------------------------------------------+
|INSPECT GROUND CONNECTION                  |        |* Open circuit in wire harness between    |
|Is there continuity between terminal 3 and |-->NO-->|  terminal 3 of switch and body ground    |
|body ground?                               |        |* Body ground faulty                      |
+----------+--------------------------------+        +------------------------------------------+
           |
          Yes
           |
+----------+--------------------------------+        +------------------------------------------+
|INSPECT SWITCH OPERATION                   |        |* Short circuit in wire harness between   |
|Is there battery voltage between terminal 6|-->NO-->|  Term 6 of switch and term 10 of computer|
|and body ground with main switch turned on?|        |* Inspect main switch                     |
+----------+--------------------------------+        +------------------------------------------+
           |
          Yes
           |
+----------+--------------------------------+        +------------------------------------------+
|INSPECT INDICATOR LIGHT OPERATION          |        |* Inspect main switch                     |
|Connect Terminal 4 to body ground.         |-->NO-->|                                          |
|Does indicator light with main switch on?  |        |                                          |
+----------+--------------------------------+        +------------------------------------------+
           |
          Yes
CONTROL SW |
+----------+--------------------------------+        +------------------------------------------+
|INSPECT GROUND CONNECTION                  |        |* Open circuit in wire harness between    |
|Is there continuity between terminal 2 and |-->NO-->|  terminal 2 and body ground              |
|body ground                                |        |* Body ground faulty                      |
+----------+--------------------------------+        +------------------------------------------+
           |
          Yes
           |
+----------+--------------------------------+        +------------------------------------------+
|INSPECT SET/COAST SWITCH OPERATION         |        |* Inspect control switch                  |
|Is there continuity between terminal 3 and |-->NO-->|                                          |
|body ground with set/coast switch on?      |        |                                          |
+----------+--------------------------------+        +------------------------------------------+
           |
          Yes
           |
+----------+--------------------------------+        +-------------------------------------------+
|INSPECT SET/COAST SWITCH OPERATION         |        |* Short Circuit in wire harness between    |
|Is there continuity between terminal 3 and |-->YES->|  terminal 3 of control switch and terminal|
|body ground with set/coast switch off?     |        |  17 of computer                           |
+----------+--------------------------------+        +-------------------------------------------+
           |
          No
COMPUTER   |
+----------+--------------------------------+
|Disconnect connector from computer and     |
|inspect connector on wire harness side as  |
|follows                                    |
+----------+--------------------------------+
           |
           |
           |
+----------+--------------------------------+        +-------------------------------------------+
|INSPECT POWER SOURCE                       |        |* Open circuit in wire harness between     |
|Is there battery voltage between term 10   |-->NO-->|  terminal 10 of computer and terminal 6   |
|and body ground with main switch turned on?|        |  of main switch                           |
+----------+--------------------------------+        +-------------------------------------------+
           |
          Yes
           |
+----------+--------------------------------+        +-------------------------------------------+
|INSPECT GROUND CONNECTION                  |        |* Open circuit in wire harness between     |
|Is there continuity between terminal 13 and|-->NO-->|  terminal 13 and body ground              |
|body ground?                               |        |* Body ground faulty                       |
+----------+--------------------------------+        +-------------------------------------------+
           |
          Yes
           |
+----------+--------------------------------+        +-------------------------------------------+
|INSPECT INDICATOR LIGHT CIRCUIT            |        |* Open circuit in wire harness between     |
|Connact terminal 3 to body ground          |-->NO-->|  terminal 3 of computer and terminal 4 of |
|Does indicator light with main switch on?  |        |  main switch                              |
+----------+--------------------------------+        +-------------------------------------------+
           |
          Yes
           |
+----------+--------------------------------+        +-------------------------------------------+
|INSPECT SET/COAST SWITCH CIRCUIT           |        |* Open circuit in wire harness between     |
|Is there continuity between terminal 17 and|-->NO-->|  terminal 17 of computer and terminal 3 of|
|body ground with set/coast switch on?      |        |  control switch                           |
+----------+--------------------------------+        +-------------------------------------------+
           |
          Yes
           |
+----------+--------------------------------+        
|Replace Computer!                          |
+----------+--------------------------------+