bulb TOYOTA CAMRY V20 1986 Service Information

Check wiring between ECU terminal T (T1) and check
connector terminal TE 1, and ECU
terminal E 1 and check connector terminal El. Is there diagnostic code output when check
connector terminals TE 1 and E 1 and short
circuited? Does ºCHECKº engine warning light come on when
ECU terminal W is grounded to the body?
Does ºCHECKº engine warning tight come
on when ignition switch is at ON?
Check bulb, fuse and wiring between ECU and
ignition switch.
Does ºCHECKº engine warning light go out after
repair according to malfunction code? Does ºCHECKº engine warning light go off when
the engine is started?
Check wiring between ECU and ºCHECKº
engine warning light.Check wiring between
ECU terminal El and body
ground.
Cancel out diagnostic code. Further repair required.Try another
ECU.Try another
ECU.
Repair or replace.Repair or replace.
System Normal
System Normal
System OKRepair.
BAD
BAD
BAD
YES YES
YESYES
YES
± EFI SYSTEMDiagnosis SystemFI±30

To Ignition SW
IG Terminal
Fuse
Relay
SW2 SolenoidVoltmeter [A]
[B]
[C] SW1
Ohmmeter
SW
INTRODUCTION±HOW TO PERFORM FOR SYSTEM INSPECTION
A±5
6
Wire Harness Repair Manual (RM1022E)
HOW TO PERFORM FOR SYSTEM INSPECTION
This inspection procedure is a simple troubleshooting which should be carried out on the vehicle during
system operation and is based on the assumption of system component trouble
Always inspect the trouble taking the following items into consideration:

Ground point fault

Open or short circuit of the wire harness

Connector or terminal connection fault

Fuse or fusible link fault
NOTICE:

This is an on±vehicle inspection during system operation.
Therefore, inspect the trouble with due regard for safety.

If connecting the battery directly, be careful not to cause a short circuit, and select the applicable
voltage.
1. Voltage Check
(a)Establish conditions in which voltage is present at the
check point.
Example:
[A] ± Ignition SW on
[B] ± Ignition SW and SW 1 on
[C] ± Ignition SW, SW 1 and Relay on (SW 2 off)
(b)Using a voltmeter, connect the negative (±) lead to a
good ground point or negative (±) battery terminal
and the positive (+) lead to the connector or
component terminal. This check can be done with a
test bulb instead of a voltmeter.
2. Continuity and Resistance Check
(a)Disconnect the battery terminal or wire so there is no
voltage between the check points.
(b)Contact the two leads of an ohmmeter to each of the
check points.
A

Diode Ohmmeter
Diode Ohmmeter
Digital Type Analog Type
Bulb Ohmmeter
A±6
INTRODUCTION±HOW TO PERFORM FOR SYSTEM INSPECTION
7
Wire Harness Repair Manual (RM1022E)
If the circuit has diodes, reverse the two leads and check
again.
When touching the negative (±) lead to the diode positive
(+) side and the positive (+) lead to the negative (±) side,
there should be continuity. When touching the two leads in
reverse, there should be no continuity.
HINT: Specifications may vary depending on the type of
tester, so refer to the tester's instruction manual before
performing the inspection.
Check LED (Light Emitting Diode) in the same manner as
that for diodes.
HINT:

Use a tester with a power source of 3V or greater to
overcome the circuit resistance.

If a suitable tester is not available, apply battery
voltage and check that the LED lights up.
(c)Use a volt/ohmmeter with high impedance (10kW/V
minimum) for troubleshooting of the electrical circuit.
3. Bulb Check
(a)Remove the bulb.
(b)There should be continuity between the respective
terminals of the bulb together with a certain amount
of resistance.
(c)Apply the two leads of the ohmmeter to each of the
terminals.
(d)Apply battery voltage and check that the bulb light up.
A

Fuse Case Test Bulb
Short [A]
SW1
Short [B]
Relay
Light
Short [C]
SW2 SolenoidDisconnect
Disconnect DisconnectTo Ignition SW
IG Terminal
INTRODUCTION±HOW TO PERFORM FOR SYSTEM INSPECTION
A±7
8
Wire Harness Repair Manual (RM1022E)
4. Finding a Short Circuit
(a)Remove the blown fuse and eliminate all loads from
the fuse.
(b)Connect a test bulb in place of the fuse.
(c)Establish conditions in which the test bulb comes on.
Example:
[A] ± Ignition SW on
[B] ± Ignition SW and SW 1 on
[C] ± Ignition SW, SW 1 and Relay on (Connect the Relay)
and SW 2 off (or disconnect SW 2)
(d)Disconnect and reconnect the connectors while
watching the test bulb. The short lies between the
connector where the test bulb stays lit and the
connector where the bulb goes out.
(e)Find the exact location of the short by lightly shaking
the problem wire along the body.
CAUTION:
(a)Do not open the cover or the case of the ECU
unless absolutely necessary. (If the IC terminals
are touched, the IC may be destroyed by static
electricity.)
(b)When replacing the internal mechanism (ECU
part) of the digital meter, be careful that no part of
your body or clothing comes in contact with the
terminals of leads from the IC, etc. of the
replacement part (spare part).
A