Contents: No connection with ECU 🠛 The engine does not start or starts…🠛 Engine idling problems 🠛 Deterioration of the vehicle's…🠛 Summary table of faults 🠛 Air supply system (boost system and…🠛 Fuel supply system 🠛 Driver-defined parameters 🠛 Ignition system - pre- and…🠛 Ignition system/pre- and…🠛 Emission control system and on-board…🠛 Refrigeration circuit 🠛 Driver-defined parameters 🠛 Driver-defined parameters 🠛
No connection with ECU
Test the diagnostic tool on another vehicle.
Check it out;
- communication between the diagnostic tool and the vehicle's diagnostic connector (good condition of wiring);
- fuses for protecting the injection system, engine and passenger compartment circuits.
Make sure there is +12 8 battery voltage on pin 16 and ground on pin 5 and pin 4 of the diagnostic connector.
Correct the problem if necessary.
With the ignition off, disconnect the injection system ECU connector, connect the universal contact board and check for broken, damaged or shorted wires in the injection system ECU:
- connector A, contact H1 - "ground";
- connector B, contact L4 - "ground";
- connector B, contact M4 - "ground";
- contact J, connector B4 - "+" after ignition switch;
- connector B, contact H2 - contact 7 of the diagnostic connector;
- connector C, contact L3 - contact 5 of the injection lock relay;
- connector C, contact M4 - "ground".
Correct the problem if necessary (see car wiring diagrams).
The engine does not start or starts with difficulty
Note: This fault can only be corrected after a full check with a diagnostic tool (there should be no present or stored faults).
Make sure the starter speed is within normal limits (approximately 250 min⁻¹).
If this is not the case:
- check the condition of the battery, the absence of signs of oxidation and the tightness of the wire tips on the terminals;
- make sure the engine ground bus is in good condition;
- make sure that the wire connecting the battery to the starter is in good condition;
- check the battery condition;
- check if the starter is working properly.
Checking the fuel supply
Check for fuel in the tank (is the fuel level sensor working properly).
Make sure the fuel is of the appropriate quality.
Check for pinched hoses (especially after removal).
Check the condition of the fuel filter and replace it if necessary.
Make sure that the hole connecting the tank to the atmosphere is not blocked.
Make sure the fuel pump is operating properly and that fuel is reaching the fuel rail.
Check the condition of the fuel pressure regulator by measuring the pressure (3.5 bar).
Checking the air supply
Check the condition of the air intake ducts (is there any air leakage, pinched air intake pipe, etc.).
Make sure the air filter element is clean and replace the filter element if necessary.
Disconnect the hose connecting the purge solenoid valve to the intake manifold and plug the hole on the manifold to prevent air from being sucked in. If everything is OK now, replace the purge solenoid valve.
Checking the ignition system
Check the condition of the spark plugs and replace them if necessary.
Make sure the spark plug type matches the engine model.
Remove the speed and crankshaft sensor and make sure it does not touch the ring gear, (increase in installation clearance). If it did, check the condition of the engine flywheel.
Make sure the ignition coils are working properly.
Checking the exhaust system
Make sure the exhaust system is in good condition.
Remove the catalytic converters and visually inspect the condition of the internal working element (for absence of blockage).
Shake the neutralizers to ensure the integrity of the working element (if this is not the case, a metallic sound will be heard).
Engine idling problems
Note: This fault can only be corrected after a full check with a diagnostic tool (there should be no present or stored faults).
Checking the fuel supply
Check for fuel in the tank (is the fuel level sensor working properly).
Make sure the fuel is of the appropriate quality.
Check for pinched hoses (especially after removal).
Check the condition of the fuel filter and replace it if necessary.
Make sure that the hole connecting the tank to the atmosphere is not blocked.
Check the condition of the fuel pressure regulator by measuring the pressure (3.5 bar).
Checking the air supply
Check the condition of the air ducts (for the absence of air leaks, pinching of the air intake pipe, etc.).
Make sure the air filter element is clean and replace the filter element if necessary.
Disconnect the hose connecting the purge solenoid valve to the intake manifold and plug the hole on the manifold to prevent air from being sucked in. If everything is OK now, replace the purge solenoid valve.
Make sure the brake booster is tight (is there an air leak?).
Checking the ignition
Check the condition of the spark plugs and replace them if necessary.
Check if the spark plugs are suitable for this engine model.
Check the condition of the ignition coils.
Checking the mechanical condition of the engine
Check the oil level using the dipstick.
Check the compression in the engine cylinders.
Check the valve timing.
Note: Check the system functionality.
Deterioration of the vehicle's driving characteristics
Note: This fault can only be corrected after a full check with a diagnostic tool (there should be no present or stored faults).
Checking the fuel supply
Check for fuel in the tank (is the fuel level sensor working properly).
Make sure that the fuel is of the appropriate quality.
Check for pinched hoses (especially after removal).
Check the condition of the fuel filter and replace it if necessary.
Make sure that the hole connecting the tank to the atmosphere is not blocked.
Make sure the fuel pump is operating properly and that fuel is reaching the fuel rail.
Check the condition of the fuel pressure regulator by measuring the pressure (3.5 bar).
Checking the air supply
Check the condition of the air intake ducts (is there any air leakage, pinched air intake pipe, etc.).
Make sure the air filter element is clean and replace the filter element if necessary
Disconnect the hose connecting the purge solenoid valve to the intake manifold and plug the hole on the manifold to prevent air from being sucked in. If everything is OK now, replace the purge solenoid valve.
Checking the ignition system
Check the condition of the spark plugs and replace them if necessary.
Make sure the spark plug type matches the engine model.
Remove the speed and crankshaft sensor and make sure it does not touch the ring gear (increase in installation clearance). If it did, check the condition of the engine flywheel.
Make sure the ignition coils are working properly.
Checking the mechanical condition of the engine
Check the oil level using the dipstick.
Check the compression in the engine cylinders.
Check the valve timing.
Check the condition of the flywheel ring gear.
Make sure the engine cooling system is working properly (that the engine is operating in optimal conditions: not too cold and not too hot).
Checking the exhaust system
Make sure the exhaust system is in good condition.
Remove the catalytic converters and visually inspect the condition of the internal working element (for absence of blockage).
Shake the neutralizers to ensure the integrity of the working element (if this is not the case, a metallic sound will be heard).
Checking the chassis
Make sure the wheels rotate freely (no jamming of brake calipers or bearings).
Check your tire pressure and tread condition (is there any swelling).
