Geely EC718, EC718RV, EC715, EC715RV. Manual part — 193

Geely EC718, EC718RV, EC715, EC715RV. Manual part - 193

Step 1

Initial Inspection

Check the existence of following factors that will affect the oxygen
sensor working status:

(a)

Exhaust system leakage or blockage.

(b)

Water entering the oxygen sensor connector.

(c)

Engine working at high temperatures, exhaust pipes too hot.

Step 2

check oxygen sensor heater resistance.

(a)

Turn the ignition switch to "OFF" position.

(b)

Disconnect the oxygen sensor wiring harness connector.

(c)

Measure the oxygen sensor heater resistance.

Standard Resistance: Connectors C and D, 9 Ω/20°C(68 ºF)

(d)

Connect the oxygen sensor wiring harness connector.

Is the resistance specified value?

Replace oxygen sensor. Refer to

2.4.7.1

Post-

Catalytic Oxygen Sensor Replacement

Yes

Step 3

Measure voltage between terminal D and ground.

FE02-5358b

Post-catalytic Oxygen Sensor Harness
Connector EO03

(a)

Turn the ignition switch to "OFF" position.

(b)

Disconnect the oxygen sensor wiring harness connector.

(c)

Turn the ignition switch to "ON" position.

(d)

Measure voltage between oxygen sensor harness connector
EO03 terminal D and ground.

Standard Voltage: 11-14 V

(e)

Connect the oxygen sensor wiring harness connector EO03.

Is the voltage specified value?

Post-Catalytic oxygen sensor heater power
supply circuit fault.

Yes

Step 4

Check oxygen sensor heater control terminal Continuity.

Engine

Control System JL4G15-D

2-687

FE02-5359b

Post-catalytic Oxygen Sensor Harness
Connector EO03

ECM Harness Connector EO01

(a)

Turn the ignition switch to "OFF" position.

(b)

Disconnect the oxygen sensor wiring harness connector
EO03.

(c)

Disconnect ECM harness connector EO01.

(d)

Test Continuity between oxygen sensor wiring harness
connector EO03 terminal C and ECM harness connector
EO01 terminal No.46.

Standard Resistance: Less than 1 Ω

(e)

Connect ECM harness connector EO01.

(f)

Connect the oxygen sensor wiring harness connector EO03.

Is the resistance specified value?

ECM control circuit malfunction.

Yes

Step 5

Check ECM working circuit.

(a)

Check whether ECM power supply circuit is normal.

(b)

Check whether ECM ground circuit is normal.

Repair the faulty part.

Yes

Step 6

Replace ECM. Refer to

2.2.8.8

Engine Control Module Replacement

(a)

Replace ECM.

(b)

Carry out crankshaft position sensor self learn. Refer to

2.12.7.11

Crankshaft Position Sensor (CKP) Learn

Step 7

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 5 min.

(f)

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

2-688

Control System JL4G15-D

Engine

Intermittent Fault. Refer to

2.2.7.3

Intermittent

Fault Check

Yes

Step 8

Diagnostic completed.

5. Repair Instructions:

Replace post-catalytic oxygen sensor. Refer to

2.4.7.1

Post-Catalytic Oxygen Sensor Replacement

2.12.7.26 DTC P0171 P0172 P1167 P1171 P2187 P2188

1. DTC Descriptor:

DTC

P0171

Mixture Too Lean

DTC

P0172

Mixture Too Rich

DTC

P1167

Pre-Catalytic Oxygen Indicating Mixture Too Rich During Deceleration

DTC

P1171

Pre-Catalytic Oxygen Indicating Mixture Too Lean During Acceleration

DTC

P2187

Mixture Too Lean When idling

DTC

P2188

Mixture Too Rich When idling

Engine Control Module (ECM) controls the close-loop Air-Fuel ratio Measure system that achieves optimal combination of
performance, fuel economy and emissions control. In the close-loop mode, the engine control module monitors heated oxygen
sensor (HO

S) signal voltage and adjusts fuel supply according to the signal. Changes in fuel supply will change the value of long-

term and short-term fuel supply adjustment. Short-term fuel supply adjustment will respond to heated oxygen sensor signal voltage
and rapidly change. These changes will fine tune the fuel supply. Long-term fuel supply adjustment will respond to the trend in short-
term fuel supply adjustment. Long-term fuel adjustment adjusts the fuel supply in order to return to the center of the short-term fuel
adjustment value and controls the short-term fuel adjustment. The ideal fuel adjustment value is around 0%. A positive value indicates
that engine control module is increasing fuel supply to compensate the lean Air-Fuel mixture. A negative value indicates that engine
control module is decreasing fuel supply to compensate the rich Air-Fuel mixture.

Engine

Control System JL4G15-D

2-689

2. Conditions For Setting DTC and The Fault Location:

DTC Code

DTC Detection Strategy

Conditions For Setting The DTC

(Control Strategy)

Fault Locations

P0170
P0171
P0172
P2177
P2178
P2187
P2188

1. Fuel Adjustment Value Higher

Than Maximum Limit

2. Fuel Adjustment Value Lower

Than Minimum Limit

3. Fuel Adjustment Value Higher

Than Maximum Limit (Low-Load
Zone)

4. Fuel Adjustment Value Lower

Than Minimum Limit (Low-Load
Zone)

1. Engine slows down and enters

(DFCO) working condition.

2. ECM detected oxygen sensor signal

voltage is higher than 0.55 V.

3. Engine enters power-enriched (PE)

working condition.

4. ECM detected oxygen sensor signal

voltage is lower than 0.35 V.

5. Duration is longer than 12 s.

1. Fuel Injectors

2. Canister

3. MAP

4. TPS

5. HO

S (Pre-Catalytic)

3. Schematic:

Refer to

2.12.6.1

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 there are no other control system DTC codes.

(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 codes.