Changes in the design of 4G1 engines since 2001

Technical data of the 4G1 engine after 2001 are given in table 17.1.

Table 17.1. Technical data of the 4G1 engine after 2001

Options		Rated value
Intake air temperature sensor resistance, kOhm	20°C	2.3-3.0
	80°С	0.30-0.42
Oxygen sensor output voltage, V		0.6-1.0
Oxygen sensor resistance at 20°С, Ohm	Front	4.5-8.0
	Rear	11-18

Engine Diagnostic Trouble Codes

As soon as one of the following points in the MPI fuel injection system fails, the engine warning light comes on (pic. 17.1). If it stays on or comes on when the engine is running, check for trouble codes. Engine Diagnostic Trouble Codes are shown in Table 17.2. To test the functionality, the warning lights come on for five seconds when the ignition is switched on and then go out.

Table 17.2. Engine Diagnostic Trouble Codes

Fault code	Node being diagnosed
-	Electronic engine control unit
P0105	vacuum pressure sensor
Р0110	Inlet air temperature sensor
Р0115	coolant temperature sensor
P0120	Throttle position sensor
P0125	Feedback system
P0130	Front oxygen sensor
P0135	Front oxygen sensor heater
P0136	Rear oxygen sensor
P0141	Rear oxygen sensor heater
P0170	Engine power system
P0201	Nozzle 1
P0202	Nozzle 2
P0203	Nozzle 3
P0204	Nozzle 4
P0300	Interruptions in ignition
P0301	Interruptions in the ignition of cylinder 1
P0302	Misfiring cylinder 2
P0303	Misfiring cylinder 3
Р0304	Misfiring cylinder 4
P0325	Knock sensor
P0335	Crank angle sensor
P0340	Camshaft Angle Sensor
Р0403	EGR solenoid valve
Р0420	Catalyst
Р0421	Catalyst
P0443	Purge air control solenoid valve
P0500	Vehicle speed sensor
P0505	Idle control system
R1610	Electronic engine lock

Technology for checking components and assemblies

The technology for checking components and assemblies is given in Table 17.3.

Table 17.3. Checking units and assemblies

Checking the engine control unit connector

The voltage values at the connector terminals of the engine control unit are shown in Table 17.4.

Table 17.4. Voltage values at the terminals of the connector of the engine control unit

Basic idle speed adjustment

1. The standard idle speed is set by the manufacturer using the speed adjusting bolt (SAS), so no such adjustment is necessary.

2. If the setting is deliberately changed, the idle speed may increase or decrease if the engine is under load, such as from an air conditioner. In this case, you need to make adjustments as described below.


3. Adjustment is carried out only after the performance of the spark plugs, injectors, idle drive with amplifier, compression, etc. has been checked.

4. Connect the MUT-II tester to the diagnostic (16-pole) connector.

5. Start the engine and let it idle.

6. Select item 30 of the Tester Verification Test.

Attention! The ISC stepper motor remains in the initial stage so that the main idle speed can be adjusted.

7. Check the idle speed. Rated value: 750±50 rpm.

Attention! For a new car (with mileage less than 500 km) engine speed can be 20-100 rpm lower, however, adjustment is not necessary in this case. If the engine stalls or the engine speed is too low even though the vehicle has been driven for more than 500 km, the throttle valve is probably clogged and needs to be cleaned.

8. If the measured value does not correspond to the nominal value, adjust it with the speed adjusting bolt (SAS) (pic. 17.2).



9. Press the reset button on the MUT-II and exit the ISC stepper motor from test mode.

Attention! If this is not done, the test mode will continue for 27 minutes.

10. Turn off the ignition.

11. Disconnect the MUT-II tester.

12. Start the engine again and let it idle for 10 minutes. Check idle speed.

Nozzle

The nozzle is shown in fig. 17.3.