Engine management system Chevrolet Aveo 1.5 (T250)

Description of the idle control circuit
The ECM controls engine idle through the idle airflow valve (IAC). To increase the idle speed of the ECM, the IAC rod comes out of its socket, allowing more...

Diagnostic Instructions
If the idle speed is too high, stop the engine. Pull out the IAC idle control knob fully using the IAC actuator. Start the engine. If the idle speed is above...

Initial setting of idle system parameters
Each time the battery cable or connector is disconnected or replaced, the following information collection procedure must be carried out. Switch on the...

Removing the idle air control valve
Caution: Do not attempt to remove the protective cap to re-adjust the top bolt. Incorrect adjustment can damage the idle air control valve (IAC) or throttle...

Idle Air Control Valve Installation
Caution: When installing a new IAC valve, make sure it is replaced with an identical part. The IAC valve stem geometry and diameter are designed for the...

Manifold absolute pressure sensor
The control system consists of sensors that provide detailed information about the state of the engine systems, an electronic control unit and actuators....

Inlet air temperature sensor
Inlet air temperature sensor (IAT) is a thermistor with a negative temperature coefficient of resistance. The sensor resistance is 4,500 ohms at 40°C and 70...

Coolant temperature sensor (coolant)
coolant temperature sensor (EATING) is a thermistor (a resistor with a value that changes as the temperature changes) with a negative temperature coefficient...

Oxygen sensor (unleaded fuel only)
Three-way catalysts are used to control hydrocarbons (NS), carbon monoxide (SO) and nitrogen oxides (NOx) in exhaust gases. The catalyst substance in the...

CO regulator (leaded fuel only)
CO regulator (potentiometer), is typically a variable resistor regulating carbon monoxide (SO), emissions from vehicles running on leaded fuels. On these...

Throttle position sensor (TP)
Throttle position sensor (TR) is a potentiometer connected to the throttle shaft on the throttle body. The throttle position sensor circuit consists of a 5 V...

Throttle body
Withdrawal 1. Disable «-» battery wire. 2. Remove the supply pipe from the throttle body. 3. Disconnect the throttle cable. 4. Remove the vacuum hoses to the...

Knock sensor
The knock sensor detects abnormal engine knock. The sensor is mounted on the engine block near the cylinders. The sensor produces an AC output voltage that...

Crankshaft Position Sensor (CKP)
The direct ignition system works with a magnetic crankshaft position sensor. This sensor protrudes from its mounting socket by about 1.3 mm relative to the...

Camshaft position sensor (CMP)
The camshaft position sensor sends a CMP signal to the engine control unit. The ECM uses this signal as a clock pulse to fire the injectors in sequence. The...

The engine control unit
The engine control unit (ECM), located under the passenger panel, is the control center for the fuel injection system. It constantly checks information from...

Comprehensive component diagnostics
Comprehensive component diagnostics are required to test powertrain components for intake and exhaust. Intake components Intake components are monitored for...

Ignition system
This ignition system does not use a breaker-distributor and a coil. Instead, a crankshaft position sensor is used, which sends a signal to the engine control...

Checking the ignition system
Check all spark plugs. Are there wet, cracked, burnt, or heavily soiled or incorrectly gapped spark plugs? Replace spark plugs if necessary. Check for spark...