Yes

System normal

No

Step 10

Replace the fuel injector.

(a)

Replace the fuel injector. Refer to 

2.2.8.2

 

Fuel Injector

Replacement

.

Confirm repair completed.

Next

Step 11

System normal.

2.3.7.5 Fuel Gage Inaccurate

Refer to 

11.7.6.6

 

DTC U1303 U1304

.

2.3.7.6 Surge diagnostic

Fault Definition: When the accelerator pedal position remaines unchanged, the engine power changes causing speed
increase or decrease.

Note

Prior to this diagnostic, make sure the engine control system has no DTC code.

Step 1

Initial Inspection

(a)

Check vacuum hoses, whether there is cracking, kinks and
so on.

(b)

Check engine ECM ground whether there is oxidation, loose,
incorrect location and so on.

(c)

Check whether sensor wiring harness connector is correctly
connected, and the existence of loose, poor connection and
so on.

Next

Step 2

Check whether the intake air pressure sensor is normal?

Refer to the "Control System" in the

2.2.7.17

 

DTC P0105 P0106

P0107 P0108

.

No

Repair the faulty part.

Yes

Step 3

Is the engine coolant temperature sensor working properly?

Refer to the "Control System" in the

2.2.7.19

 

DTC P0117 P0118

.

No

Repair the faulty part.

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Yes

Step 4

Check the fuel pressure, is it normal?

Refer to 

2.3.7.7

 

Fuel Pressure Testing Procedure

.

No

Check whether the pipeline is blocked, if
necessary, replace the failed component.

Yes

Step 5

Use the scan tool "Fuel Injector Cleaning and Testing Machine" function, test the performance of the cylinder
fuel injector. Check whether the fuel injectors are normal?

No

Replace damaged fuel injectors.

Yes

is

Step 6

Check whether fuel quality is normal, is the fuel contaminated?

Yes

Replace with good quality fuel.

No

Step 7

Connect scan tool, check the pre-catalytic oxygen sensor signal.

FE02-7002b

(a)

Connect scan tool.

(b)

Start engine and turn on the scan tool.

(c)

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).

(d)

Select on the scan tool: Engine / Read Data Flow / Group 1
Oxygen Sensor Voltage 1 (Pre-Catalytic Oxygen Sensors).

(e)

Observe the pre-catalytic oxygen sensor output voltage. The
data flow should fluctuate within 0.1-0.8 V.

(f)

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.

•

Observe whether there is a significant change in the pre-
catalytic oxygen sensor voltage data, as the signal
voltage will increase rapidly.

(g)

If the voltage data is always higher than 0.45 V (mixture too
rich), carry out the following steps:

•

Put gear into neutral.

•

Apply hand brake.

•

Press the accelerator pedal so the engine speed
suddenly increases to 4,000 rpm and then quickly release
the accelerator pedal.

•

Repeat the previous steps more than 3 times.

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•

Observe whether there is a significant change in the pre-
catalytic oxygen sensor voltage data, as the signal
voltage will increase rapidly.

During the above test, the oxygen sensor signal voltage should
have a significant change.

Significant voltage change?

Signal Voltage No Response

A

Signal Voltage Remains High

B

Signal Voltage Remains Low

C

Signal Voltage Normal

D

A

Replace the pre-catalytic oxygen sensor.

B

Go to step 13

C

Go to step 14

D

Step 8

Check whether the spark plug is normal?

(a)

Refer to "Ignition System" in the

2.10.7.6

 

Spark Plug

Diagnostic

.

No

Replace with the correct type of spark plug.

Yes

Step 9

Check whether the high-voltage resistance is normal?

(a)

Check whether the high-voltage resistance connection is
solid, not damaged and so on.

No

Repair the faulty part. If necessary, replace
with a new high-voltage resistor.

Yes

Step 10

Check whether the crankshaft position sensor signal tooth is correctly installed?

(a)

Check whether the crankshaft position sensor signal tooth
installation is solid. The signal tooth can not be missing, wear
and tear and so on.

No

Diagnose the faulty part. If necessary, replace
the faulty parts.

Yes

Step 11

Check whether air-conditioning system is working correctly?

(a)

Check the compression clutch engagement. Air-Conditioning
system pressure can not be too high. Check whether the air-
conditioning compressor is working properly. Refer to the

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"Air-Conditioning System" in the

8.2.7

 

Diagnostic Information

and Procedures

.

No

Repair the faulty part.

Yes

Step 12

Check whether the exhaust system is normal?

(a)

Inspect the exhaust system for blocking. Refer to the "Engine
Exhaust System" in the

2.7.5.3

 

Exhaust System Blockage

.

No

Repair the faulty part.

Yes

Go to step 15

Step 13

Check the cause for the mixture too rich.

(a)

Check whether the canister solenoid valve is normally turned
on.

(b)

Check whether there is fuel injectors leakage.

(c)

Check whether the air filter is blocked.

(d)

Check whether there is intake manifold clogging or
deformation.

(e)

Check whether the engine oil is contaminated by fuel.

(f)

Check whether the fuel pressure is too high.

(g)

Check whether the intake manifold absolute pressure sensor
is normal.

(h)

Check whether the engine coolant temperature sensor is
normal.

The existence of the above faults?

No

Go to step 15

Yes

Repair the faulty part.

Step 14

Check the cause for the mixture too lean.

(a)

Check whether there is a vacuum leak.

(b)

Check the existence of broken tubes.

(c)

Check whether the fuel injectors is blocked.

(d)

Check whether intake manifold absolute pressure sensor is
abnormal.

(e)

Check whether the engine coolant temperature sensor is
abnormal.

(f)

Check whether the fuel is contaminated.

The existence of the above faults?

Yes

Repair the faulty part.

No

Step 15

Road test the vehicle to confirm that the fault has been ruled out.

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