Content .. 142 143 144 145 ..

Chery Tiggo. Manual - part 144

Check reference values between ECM terminals and ground under the following conditions:

ECM TERMINAL NO.

ITEM

CONDITION

DATA

Sensor (GND)

Ignition switch on

Approximately 0 V

Regulated sensor supply 1

5 V

Air flow sensor

• Engine is running

• Warm-up condition ECT:
78°C

• Idle: 795 RPM

• IAT: 36°C

• IAT signal: 1.88 V

• Approximately 322 kg/h

• Approximately 1.39 V

• Engine is running

• Warm-up condition ECT:
52°C

• Idle: 910 RPM

• IAT: 30°C

• IAT signal: 2.17 V

• Approximately 420 kg/h

• 1.52 V

On Board Diagnostic Logic
• Self-diagnosis detection logic.

DTC NO.

DTC DEFINITION

DTC DETECTION

CONDITION

DTC SET

CONDITION

POSSIBLE CAUSE

P0103

Mass or Volume Air

Flow (MAF) circuit

high input

Ignition switch on or

engine is running

ECM detected that
the input signal is
out of the
acceptable range.

• MAF sensor

• Harness or
connectors

• ECM

DTC Confirmation Procedure:

Before performing the following procedure, confirm that battery voltage is more than 12 V.

• Turn ignition switch off.

• Connect the X-431 scan tool to the Data Link Connector (DLC) - use the most current software available.

• Turn ignition switch on.

• With the scan tool, record and erase stored DTCs in the ECM.

• Start engine and warm it to normal operating temperature, then select view DTC and data stream.

• If the DTC is detected, the DTC condition is current. Go to Diagnostic Procedure - Step 1.

• If the DTC is not detected, the DTC condition is intermittent (See Diagnostic Help and Intermittent DTC Trou-

bleshooting in Section 03 Electronic Engine Controls for more information.

NOTE :
While performing electrical diagnosis & testing, always refer to the electrical schematics for specific circuit
and component information.

DIAGNOSIS & TESTING

Diagnostic Procedure

CHECK GROUND CONNECTIONS

• Turn ignition switch off.

• Loosen and retighten ground screws on the body (See Ground Inspection in Section 03 Electronic Engine Con-

trols).

• Inspect ground connections E-207 and E-208 mounting position (See Vehicle Wiring Harness Layout - Engine

Room Harness (With 2.0L Engine) in Section 16 Wiring).

Are the ground connections OK?

Yes

Go to the next step.

Repair or replace ground harness or connections.

CHECK INTAKE SYSTEM

• Check the following for connection:

− Air cleaner
− Intake air duct

Is the check result normal?

Yes

Go to the next step.

Clean or replace the components.

CHECK MAF SENSOR ELECTRICAL CONNECTOR

• Disconnect the MAF sensor electrical connector (1).

• Inspect the electrical connector for damage.

Is the electrical connector OK?

Yes

Go to the next step.

Repair or replace the electrical connector

as necessary.

DIAGNOSIS & TESTING

VISMD030005

CHECK MAF SENSOR POWER SUPPLY CIRCUIT

• Turn ignition switch on.

• Check voltage between MAF sensor terminal 4 and

ground in the MAF sensor electrical connector
E-009.

• 5 V should exist.

Is the check result normal?

Yes

Go to step 6.

Go to the next step.

DETECT MALFUNCTIONING PART

• Check harness for short to power between air flow sensor and ECM.

Is the check result normal?

Yes

Go to the next step.

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

CHECK MAF SENSOR GROUND CIRCUIT FOR SHORT

• Turn ignition switch off.

• Disconnect ECM harness connector.

• Check harness continuity between MAF sensor terminal 3 and ECM terminal 17.

• 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 short to power in harness or connectors.

CHECK MAF SENSOR OUTPUT SIGNAL CIRCUIT

• Check harness continuity between MAF sensor terminal 5 and ECM terminal 37.

• 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 short to power in harness or connectors.

DIAGNOSIS & TESTING

LTSMD030042

CHECK MAF SENSOR

• Install all removed parts.

• Check MAF signal in data stream with the X-431.

ECM

TERMINAL

NO.

ITEM

CONDITION

DATA

Air

flow

sensor

• Engine is

running

• ECT: 78°C

• Idle: 795

RPM

• IAT: 36°C

• IAT signal:

1.88 V

Approximately

322 kg/h

Approximately

1.39 V

• If without the X-431, check voltage between MAF sensor terminal 5 and ground.

ECM

TERMINAL

NO.

ITEM

CONDITION

DATA

(AVERAGE

VOLTAGE)

37 (MAF

sensor

connector

terminal 5)

Air

flow

sensor

• Engine is

running

• ECT: 78°C

• Idle: 795

RPM

• IAT: 36°C

• IAT signal:

1.88 V

Approximately

1.39 V

Is the signal voltage of MAF normal?

Yes

Go to the next step.

Replace MAF sensor.

CHECK DTC

• With the X-431 scan tool, read ECM DTCs.

• See DTC Confirmation Procedure.

Is DTC P0103 still present?

Yes

Replace the ECM.

NOTE : The Immobilizer control module must be matched to the new ECM (See ECM Removal & Instal-

lation in Section 03 Electronic Engine Controls).

The system is now operating properly.
Reassemble the vehicle and road test to verify the customers complaint is repaired.

DIAGNOSIS & TESTING

Content .. 142 143 144 145 ..