Geely EC718, EC718RV, EC715, EC715RV. Manual part — 66

Vehicle Speed Sensor Harness Connector EN21

1

2

3

FE02-5100

b

(a)

Turn the ignition switch to "OFF" position.

(b)

Disconnect speed sensor wiring harness connector EN21.

(c)

Measure resistance between vehicle speed sensor harness
connector EN21 terminal No.2 and a reliable ground. Check
whether the circuit is short to ground.

Standard Resistance: Less than 1 Ω

Is the value specified value?

No

Check whether there is an open circuit
between the vehicle speed sensor terminal
No.2 and a reliable ground. Repair the faulty
part.

Yes

Step 5

Replace the vehicle speed sensor.

Next

Go to step 8

Step 6

Check ECM power supply circuit.

(a)

Check whether ECM power supply circuit is normal.

(b)

Check whether ECM ground circuit is normal.

No

Repair the faulty part.

Yes

Step 7

Replace ECM.

Next

Step 8

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)

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 9

Diagnostic completed.

Engine

Control System JL4G18-D

2-179

2.2.7.36 DTC P0506-P0509 P0511

1. DTC Descriptor:

DTC

P0506

Controlled Idle Speed Lower Than Target Idle Speed

DTC

P0507

Controlled Idle Speed Higher Than Target Idle Speed

DTC

P0508

Stepper Motor Driver Pin Short to Ground

DTC

P0509

Stepper Motor Driver Pin Short to Power Supply

DTC

P0511

Stepper Motor Driver Pin Circuit Open

ECM controls the engine idle speed by regulating the IAC valve core shaft position. IAC valve's two internal coils are driven by the
stepper motors. idle air control valve's move is controlled by 4 circuits. ECM's driver controls idle air control valve two wires polarity
via these circuits. ECM commands the IAC valve stepper motor rotate clockwise or counterclockwise. IAC valve motor is connected
to the idle air control spool shaft through the driver screw. ECM sends electrical pulses to the IAC valve coils to allow the core shaft
stretch into or contract out of the throttle body channel. Through the core shaft, air flow increases, so the engine speed increases.
When the pivotal stretches, the air flow decreases, therefore the engine speed is reduced. If the engine control module detects the
engine speed is not in the expected range, the DTC codes will be set.

ECM harness connector EN01 terminals No. 21,22,35,36 are connected to IAC valve harness connector EN17 terminals B, A, C,
D.

2. Conditions For Setting DTC and The Fault Location:

DTC

Code

DTC Detection Strategy Conditions For Setting The DTC (Control Strategy)

Fault Locations

P0506

Idle actuator stays at a
small opening position.

1. Static target idle speed and the actual idle speed

difference is less than 200 rpm.

2. Idle speed integral part is equal to the minimum.

3. Canister solenoid valve opening is less than 100%.

4. The engine is at idle speed.

5. The vehicle speed is equal to 0.

6. Engine coolant temperature is higher than 80.3°C

(176.5 ºF) .

7. Intake air temperature is higher than 20.3°C (68.5 ºF).

1. Idle Air Control Valve

Circuit

2. Idle Speed Control

Valve

3. Intake System

4. ECM

2-180

Control System JL4G18-D

Engine

DTC

Code

DTC Detection Strategy Conditions For Setting The DTC (Control Strategy)

Fault Locations

P0507

Idle actuator stays at a big
opening position.

1. Static target idle speed and the actual idle speed

difference is less than 100 rpm.

2. Idle speed integral part is equal to the maximum.

3. Canister solenoid valve opening is less than 100%.

4. The engine is at idle speed.

5. The vehicle speed is equal to 0.

6. Engine coolant temperature is higher than 80.3°C

(176.5 ºF) .

7. Intake air temperature is higher than 20.3°C (68.5 ºF).

P0508

Hardware Circuit Checks

One stepper motor pin is short to ground.

P0509

One stepper motor pin is short to battery positive cable.

P0511

One stepper motor pin is in an open circuit.

3. Schematic:

Idle Control Valve

Engine

Control

Module

FE02-5101b

Engine

Control System JL4G18-D

2-181

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

Use scan tool to carry out idle air control valve action test.

(a)

Connect scan tool to the datalink connector.

(b)

Start engine and turn on the scan tool.

(c)

Select the following: the "Engine"/"Action Test"/"Idle Speed
Control".

(d)

Use scan tool "Function Test" command to enable IAC valve
opening. Increase the speed up to 1,800 rpm and decrease
to 800 rpm, and then increase to 1,800 rpm.

Whether the engine speed follows the instructions rise and fall
steadily?

Yes

Intermittent Fault. Refer to

2.2.7.4

Fault

Symptom Table

No

Step 2

Check the following items.

(a)

Throttle body damage or blockage.

(b)

Is idle air control channel blocked?

(c)

Is there too much residue on the throttle?

(d)

Is there too much residue on the throttle?

(e)

Is there too much residue on the idle air control core shaft?

(f)

Is intake blocked?

Any above mentioned fault?

Yes

Repair the faulty parts. Go to step 10

No

Step 3

Check idle speed control valve.

Idle Control Valve

FE02-5102b

(a)

Turn the ignition switch to "OFF" position.

(b)

Disconnect idle speed control valve wiring harness connector
EN17.

(c)

Measure idle speed control valve resistance.

Tester Connection

Standard Value

AD, BC

40-50 Ω

AC, BD

10 kΩ or higher

(d)

Connect idle speed control valve wiring harness connector
EN17.

Voltage normal?

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Control System JL4G18-D

Engine