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Chery Tiggo. Manual - part 106

CHECK UPSTREAM O

SENSOR SIGNAL CIRCUIT

• Disconnect ECM harness connector.

• Check harness continuity between the following terminals.

COMPONENT TERMINAL

ECM TERMINAL

SENSOR TERMINAL

TERMINAL

• Continuity should exist.

• Check harness for short to power.

Is the check result normal?

Yes

Go to the next step.

Repair or replace circuit for an open or short to power in harness or connectors.

CHECK THE FUEL PRESSURE

• Release fuel pressure to zero.

• Install fuel pressure gauge (2) and check fuel

pressure.

• Observe the following fuel pressures when testing (See Fuel Pressure Test in Section 04 Fuel Delivery).

FUEL PRESSURES

Key On

400 kPa (4.0 bar)

Key Off

380 kPa (3.8 bar) in 10 minutes

Engine: Idle

400 - 420 kPa (4.0 - 4.2 bar)

DIAGNOSIS & TESTING

BESM030020

Is the check result normal?

Yes

Go to step 7.

Go to the next step.

DETECT MALFUNCTIONING PART

• Check the following:

− Fuel pump and circuit
− Fuel pressure regulator

Is the check result normal?

Yes

Go to the next step.

Repair or replace.

CHECK MAF/MAP SENSOR

• Turn ignition switch off.

• Install all removed parts.

• For 1.8L engine, check MAF signal in data stream.

TERMINAL NO.

ITEM

CONDITION

DATA (AVERAGE DC

VOLTAGE)

MAF sensor

• Engine is running

• ECT: 78°C

• Idle: 795 RPM

• IAT: 36°C

• IAT signal: 1.88 V

322 kg/h

1.39 V

• For 1.6L engine, check MAP sensor signal voltage.

TERMINAL

NO.

ITEM

CONDITION

DATA (DC

VOLTAGE)

MAP

sensor

Engine:

Running

• Engine
running: Idle

• Press

accelerator
pedal slowly.

Approximately

1.3 V

• Press
accelerator
pedal quickly.

Up to

approximately

4 V

(Instantaneous)

Is the check result normal?

Yes

If with the X-431, go to the next step.
If without the X-431, go to step 9.

Check connectors for damaged or air flow signal circuit for short to power.

DIAGNOSIS & TESTING

PERFORM ACTIVE TEST FUNCTION

• Start engine.

• Select ⬙ACTIVE TEST⬙ menu.

• Perform injector active test.

• Make sure that each test produces a momentary engine speed drop.

Is the check result normal?

Yes

Go to step 11.

Go to the next step.

CHECK FUNCTION OF INJECTOR

• Listen to each injector operating sound.

• Operating sound should exist.

Is the check result normal?

Yes

Go to step 11.

Go to the next step.

10.

CHECK INJECTOR CONTROL CIRCUIT

• Turn ignition switch off.

• Disconnect injector harness connector (1).

• Disconnect ECM harness connector.

• Check harness for a short to ground between the following terminals.

INJECTOR NO.

ECM

TERMINAL

INJECTOR

TERMINAL

DIAGNOSIS & TESTING

BESM040006

• Continuity should not exist.

Is the check result normal?

Yes

Go to the next step.

Repair or replace circuit for short to ground in harness or connectors.

11.

CHECK INJECTOR RESISTANCE

• Disconnect injector harness connectors (See Fuel Pressure Test in Section 04 Fuel Delivery).

• Check the resistance of the injectors.

INJECTOR

NO.

INJECTOR

TERMINAL

RESISTANCE

(APPROXIMATELY)

⍀ (20°C)

1 & 2

Is the check result normal?

Yes

Go to the next step.

Replace injector.
Go to step 13.

12.

CHECK INJECTOR

WARNING!

Confirm that the engine is cooled down and there are no fire hazards near the vehicle.

• Remove fuel delivery rail with injectors (See Fuel Injector Rail Removal & Installation 1.6L & 1.8L & 2.0L in

Section 04 Fuel Delivery).

NOTE :
Be careful not to drop the fuel injectors when removing the fuel delivery rail.
• Keep fuel hose and all injectors connected to injector rail.

• Disconnect all injector harness connectors.

• Disconnect all ignition coil harness connectors.

• Prepare pans or saucers under each injector.

• Crank engine for about 3 seconds.

• Make sure fuel does not drip from injector.

Is the check result normal?

Yes

Go to next step.

Replace the injectors from which fuel is dripping. Always replace O-ring with new one.

DIAGNOSIS & TESTING

Content .. 104 105 106 107 ..