Geely EC718, EC718RV, EC715, EC715RV. Manual part — 206

2. Conditions For Setting DTC and The Fault Location:

DTC Code

DTC Detection Strategy

Conditions For Setting The DTC

(Control Strategy)

Fault Locations

P0420

Hardware Circuit Checks

Coolant temperature is higher than
70°C (158 ºF), and the fuel system is
in close-loop mode. After driving
some distance and stop the vehicle,
run the engine at idle, the system
compares the Pre-Catalytic and
Post-Catalytic oxygen sensor
signals to calculate three-way
catalyst converter oxygen storing
time. When the oxygen storing time
is less than the threshold, the system
reports a fault.

1. Pre-Catalytic Oxygen Sensor

2. Post-Catalytic Oxygen Sensor

3. Three-Way Catalytic Converter

4. Exhaust Leak

3. Schematic:

Refer to

2.2.6.1

Schematic

4. Diagnostic Steps:

Note

Before carrying out this diagnosis step, observe the data list on scan tool and analyze the accuracy of the data, as
these will help with quick diagnosis.

Step 1

Check whether there are control system DTC codes other than DTC P0420.

(a)

Connect scan tool to the datalink connector.

(b)

Turn the ignition switch to "ON" position.

(c)

Press the scan tool power button.

(d)

Select the following menu items: Engine/Read DTC codes.

(e)

Read DTC code

DTC Codes Shown

To Step

DTC P0420

Yes

DTC Code Other Than DTC P0420

No

No

Refer to

2.12.7.14

DTC Code Index

.

Yes

Step 2

Start engine and turn on the scan tool.

Next

Step 3

Keep the engine speed at 2,500 rpm for more than 2 min to warm up the engine, until the engine coolant
temperature reaches 80°C (176 ºF).

Engine

Control System JL4G15-D

2-739

Next

Step 4

Select on the scan tool: Engine/Read data/Group 1 oxygen sensor voltage 1 (Pre-Catalytic oxygen sensor),
Group 1 oxygen sensor voltage 2 (Post-Catalytic oxygen sensor)

Next

FE02-5092b

0V

0V

0V

0V

1V

1V

1V

1V

Deteriorated TWC

Normal TWC

Pre-catalytic

Oxygen Sensor

Post-catalytic

Oxygen Sensor

Step 5

Observe Pre-Catalytic oxygen sensor and Post-Catalytic oxygen sensor output voltages.

Whether Pre-Catalytic oxygen sensor and Post-Catalytic oxygen
sensor signal voltage is matching "Normal TWC" in the graphic?

Yes

Intermittent Fault. Refer to

2.2.7.3

Intermittent

Fault Check

.

No

Warning!

Propane gas as is a flammable gas. It is strictly prohibited to operate propane gas near a fire, otherwise it will cause a
fire.

Step 6

Test the oxygen sensor signal.

(a)

If the voltage data is consistently below 0.45 V (mixture too
lean), carry out the steps as following:

•

Spray proper amount of propane gas into the intake.

2-740

Control System JL4G15-D

Engine

•

Inspect whether the sensor voltage data is changed
significantly, as the signal voltage will increase rapidly.

Pre-Catalytic

Oxygen Sensor

Signal Voltage

Post-Catalytic Oxygen
Sensor Signal Voltage

To Step

Obvious Change

No Change

A

No Change

Obvious Change

B

Obvious Change

No Change

C

No Change

No Change

D

B

Replace the pre-catalytic oxygen sensor.
Refer to

2.4.7.2

Pre-Catalytic Oxygen Sensor

Replacement

.

C

Go to step 9

D

Check the cause for engine air-fuel ratio too
lean/too rich. Refer to

2.12.7.4

Symptoms

Table

A

Step 7

Check whether there is exhaust leakage.

Yes

Repair the faulty part. Go to step 11

No

Step 8

Replace the three-way catalytic converter. Refer to

2.7.6.2

Three-way Catalytic Converter Replacement

.

Next

Go to step 11

Step 9

Check whether there is exhaust leakage.

Yes

Repair the faulty part. Go to step 11

No

Step 10

Replace the post-catalytic oxygen sensor. Refer to

2.4.7.1

Post-Catalytic Oxygen Sensor Replacement

.

Next

Step 11

Use scan tool to confirm whether the DTC code is stored again.

(a)

Connect scan tool to the datalink connector.

(b)

Turn the ignition switch to "ON" position.

(c)

Clear DTC code.

(d)

Start and run the engine at idle speed to warm up the engine
for at least 5 min.

(e)

Road test the vehicle for at least 10 min.

Engine

Control System JL4G15-D

2-741

(f)

Read control system DTC code again to confirm that the
system has no DTC code.

No

Intermittent Fault. Refer to

2.2.7.3

Intermittent

Fault Check

.

Yes

Step 12

Diagnostic completed.

2.12.7.39 DTC P0458 P0459

1. DTC Descriptor:

DTC

P0458

Canister Control Valve Control Circuit Short To Ground or Open

DTC

P0459

Canister Control Valve Control Circuit Short To Power Supply

EVAP solenoid valve absorbs fuel vapor from the evaporative emission Canister to the intake manifold. EVAP solenoid valve is
controlled by the pulse width modulation (PWM). The circuit consists of:

–

Operating Voltage: Battery voltage passes through ECM controlled main relay terminal No.87 to reach EVAP solenoid harness
connector EN24 terminal A.

–

ECM control circuit: EVAP solenoid valve wiring harness connector EN24 terminal B is connected to ECM harness connector
EN01 terminal No.57. ECM has an internal driver circuit to control the solenoid valve ground. Driver circuit is equipped with a
ECM feedback circuit. ECM monitors the feedback voltage to determine whether the control circuit is open, short to ground or
short to power supply.

2. Conditions For Setting DTC and The Fault Location:

DTC Code

DTC Detection Strategy

Conditions For Setting The DTC

(Control Strategy)

Fault Locations

P0458

Hardware Circuit Checks

At idle conditions, canister solenoid
valve inoperative, canister solenoid
valve circuit short to ground or open,
DTC code set.

1. Canister Solenoid Valve

Circuit

2. Solenoid Valve

3. ECM

P0459

Hardware Circuit Checks

At idle conditions, canister solenoid
valve inoperative, canister solenoid
valve circuit short to power supply,
DTC code set.

1. Canister Solenoid Valve

Circuit

2. Solenoid Valve

3. ECM

2-742

Control System JL4G15-D

Engine