Electronic Control Syste M; General - Toyota COMPUTER-CONTROLLED SYSTEM Training Manual

ELECTRONIC CONTROL SYSTEM - Genera l
ELECTRONIC CONTROL SYSTE M
GENERAL
The engine control system can be divided into
three groups : sensors (and the signals output by
them), the ECU, and actuators . This section
describes only the sensor (signal) systems .
ECU functions are divided into EFI control, ESA
control, ISC control, diagnostic function, fail-safe
function, back-up function and others . Each of
these functions is covered in a separate section
of this manual .
Actuator functions are also covered in a
separate section .
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The following table shows the specifications for
the 4A-FE engine . Information on sensors (and
their signals) marked with a circle in the
"APPENDIX" column is included in the
specifications for each engine in the APPENDIX
section (page 188) at the back of this manual .
Sensors (signals) covered in Step 2, vol . 5 (EFI),
are covered in outline form only in this manual .
If there is a circle in the "STEP 2(EFI)" column in
the following table, refer to the Step 2, vol . 5
(EFI), for a detailed explanation of the relevant
sensors (and their signals) .
SENSORS (SIGNALS)
PAG E
(THI S
MANUAL)
ITEM
REMARK
APPENDIX
STEP 2
(EFI )
Engine without steppe r
motor type ISC valve
15 0
Power circuitry
Engine with steppe r
motor type ISC valve
1 6
VC circuitry
16
0
Ground circuitry
16
0
Manifold pressure senso r
(vacuum sensor)
17
0
Vane type
1 8
Air flow meter
Optcal Karman vorte x
type
2 1
Hot-wire type
21- 1
Throttle
On-off type
2 2
position sensor
Linear type
23 0
In-distributor type
2 4
G and NE signa l
enerators
Cam position sensor type 2 7
g
Separate type
2 8
Water temperature sensor
3 0
Intake air temperature sensor 3 0
Oxygen sensor
Zirconia element type 31
With TW C
(02 sensor)
Titania element type 3 2
Lean mixture sensor 3 3
` Specifications for Carolla AE101 4A-FE engine (Apr ., 1992)
(Continued on next page )
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