Page 962 - Workshop Manual - Tunland (2017)

04-276 DIAGNOSTICS - ENGINE CONTROL SYSTEM

04 DEFECTS

If the default wasn’t identified in the DTC (diagnosis of default code) check, and the reasons
causing the default also wasn’t identified in the basic check, then it should troubleshoot as
the following items, and then go to the relevant troubleshooting page to do it.

Fault phenomenon Possible reasons Refer to

1. CAN bus circuit
Chapter 04 Diagnosis-the
The diagnostic tool cannot 2. ECM bus circuit motor control system, the
communicate with the ECU 3. ECM ground circuit diagnostic tool cannot
communicate with the ECU
4. ECU
1. Injector

2. Intake system
3. Fuel system
Chapter 04 Diagnosis-the
4. Coolant temperature
The starter rotates but the motor control system, the
sensor
motor can’t start starter rotates but the motor
5. Intake mass flow sensor
can’t start.
6. Injector timing

7. Intake heater
8. ECM

1. Injector
2. Intake system

3. Fuel system
4. Coolant temperature Chapter 04 Diagnosis-the
The cold car starts difficultly sensor motor control system, the cold
, the car is trembled car starts difficultly, the car is
5. Intake mass flow sensor trembled
6. Injector timing

7. Intake heater
8. ECM

1. Injector

2. Intake system
Chapter 04 Diagnosis-the
Unstable idling (fluctuated) 3. Fuel system motor control system,
unstable idling (fluctuated)
4. Electronic throttle valve
5. ECM

1. ECM Chapter 04 Diagnosis-the
High idle speed (idle speed is motor control system, high
2. Intake system
not within the specified value) idle (idle speed is not within
3. Electronic throttle valve the specified value )