ENGINE AND EMISSION CONTROL SYSTEM DESCRIPTION
EF & EC-21prose procedureExhaust Gas Sensor Heater Control section applies to catalyzer model only.
Exhaust Gas Sensor Heater Control (For catalyzer model)
INPUT/OUTPUT SIGNAL LINE
Exhaust Gas Sensor Heater Control - Input/Output Signal Line
Computing layout…
Wire Details
| From | To | Color |
|---|---|---|
| crank_angle_sensor | eccs_unit | |
| air_flow_meter | eccs_unit | |
| engine_temp_sensor | eccs_unit | |
| eccs_unit | exhaust_gas_sensor_heater |
SYSTEM DESCRIPTION
The exhaust gas sensor heater helps activate the sensor quickly to stabilize closed-loop control under all operating conditions.
Fail-safe System
AIR FLOW METER MALFUNCTION
If the air flow meter output voltage is above or below the specified value, the E.C.U. senses an air flow meter malfunction. In case of a malfunction, the throttle sensor substitutes for the air flow meter. Though air flow meter is malfunctioning, it is possible to drive the vehicle and start the engine. But engine speed will not rise more than 2,000 rpm in order to inform the driver of fail-safe system operation while driving.
ENGINE TEMPERATURE SENSOR MALFUNCTION
When engine temperature sensor output voltage is below or above the specified value, engine temperature is fixed at the preset value as follows:
Engine Temperature Preset Value
| Engine condition | Engine temperature preset value °C (°F) |
|---|---|
| Start | 20 (68) |
| Running | 80 (176) |
Start
Engine temperature preset value °C (°F)20 (68)
Running
Engine temperature preset value °C (°F)80 (176)
Direct Ignition System
This system has no conventional distributor and high-tension wires. Small, very efficient ignition coils are fitted directly to each spark plug.
Direct Ignition System Schematic
Computing layout…
Wire Details
| From | To | Color |
|---|---|---|
| ignition_switch | eccs_relay | |
| eccs_relay | ecu | |
| battery | eccs_relay | |
| ignition_switch | to_starter | |
| crank_angle_sensor | ecu | |
| ecu | power_transistor | |
| power_transistor_relay | power_transistor | |
| power_transistor | ignition_coil_1 | |
| power_transistor | ignition_coil_2 | |
| power_transistor | ignition_coil_3 | |
| power_transistor | ignition_coil_4 | |
| ignition_coil_1 | spark_plug_1 | |
| ignition_coil_2 | spark_plug_2 | |
| ignition_coil_3 | spark_plug_3 | |
| ignition_coil_4 | spark_plug_4 | |
| air_flow_meter | ecu | |
| engine_temp_sensor | ecu |