Chery A11. Manual — part 109

When temperature is 800℃, impedance

is

25.0+/-10%

When temperature is -40℃, heater

impedance is

12.2+/-10%

●Detecting Method:

a、voltage signal method

Before testing oxygen sensor, engine must be under normal operation temperature.
【Note】Only digital voltmeter can be used to test oxygen sensor, otherwise oxygen sensor

will be damaged.

● During testing, the insulation may be pricked. Before testing, digital voltmeter leads

must be connected to oxygen sensor ground lead and signal lead. When engine idles and

under normal temperature, if air/fuel ratio has some difference with ideal air/fuel ratio, the

oxygen sensor output voltage will vary from low to high periodically. The voltage

periodically varies from 0.3V to 0.8V. After testing, apply silicon seal gum on pricked

area.
●

A continuously high voltmeter reading indicates an rich air/fuel ratio polluted oxygen

sensor ambient temperature silicon seal gum or antifreeze agent polluted oxygen sensor or

leaded fuel used in engine.

A continuously low voltmeter reading indicates an poor air/fuel ratio, sensor fault. A

medium reading maintained indicates a possible oxygen sensor fault.

● Remove oxygen sensor from engine. Connect a digital voltmeter lead to sensor, and

combust sensor sensitive element on propane welding torch flame. The propane flame could

isolate the sensitive element from oxygen, which will generate voltage. When sensitive

element is on flame, the voltage is approximately 1V, and when moved away the flame, the

voltage will drop to 0V. If sensor voltage does not change as specified, replace the oxygen

sensor.

◆Heating wire diagnostic

If the heater on sensor does not work, sensor pre-heating will be delayed, and computer

work time will also be prolonged. Then computer send a wrong rich air/fuel ratio signal,

wasting the fuel.

b、Ohmmeter method

Remove oxygen sensor and connect the ohmmeter between the heating wire and ground

wire. Referring to above diagram, if the resistance measured is not as specified, replace it

2.1.5 Speed sensor
◆ If speed sensor is damaged, the engine can not be started.

Speed sensor has 2 leads, one is signal lead (pin B7) and the other is ground wire (pin B6)

⑴ speed sensor
⑵ belt pulley with teetht
⑶ signal output

⑷ signal corresponding to 2

mis-teeth.

Speed sensor determines firing and fuel injection time by monitoring the teeth on the flying

wheel, engine speed and crankshaft position signal.

● Testing method

a ohmmeter method: the coil resistance is 515Ω,

b oscilloscope

method:

Use oscilloscope to monitor pulse waveform, and a voltage pulse will generate when a

tooth pass by. The flying wheel on this engine have 60-2 teeth.

2.1.6 Ignition

coil

Ignition Coil Electrical Specification

Primary coil induction

5.80±15%mH

Primary coil resistance

0.53±10%Ω

Secondary coil induction

12.8±10%kΩ

Secondary coil resistance

40.0±20%H

Testing voltage

2Vdc

Testing current

7.0Amps

Output (no load)

40kvMin

Output (50Pf load)

40.0±7%mJ

Energy storage time (reference)

6.3ms

Secondary peak value current

74mA±7%

I firing delayed time

3.6ms±3%

Coil number ratio

83:1

● Testing method

Ohmmeter method: referring to above chart and check ignition coil resistance.

● Ignition wire

Remove ignition wire and 5-8mm away from cylinder. Turn on ignition switch, start engine

and watch flame. A strong blue flame indicates a operational ignition coil. Otherwise, check

ignition coil. Using ohmmeter method, referring to above chart, check and remove injector

connector before checking.

● Monitoring each cylinder misfire

Remove each cylinder spark plug, and connect to appropriate high-tense wire, ensuring

spark plug thread reliably ground on cylinder body. Start engine and monitor spark plug

misfire.

2.1.7 Throttle position sensor (TPS)

TPS fault may cause unsmooth acceleration, engine stalling and rough idle etc. TPS has 3

leads, a current lead (Pin B22), a ground lead (Pin B23) and a signal lead (B17).
● Testing method

a ohmmeter

method:

Remove TPS connector. Depress throttle slowly and monitor resistance. Measuring

resistance at wide open throttle (WOT), resistance is 5KΩ±20% at WOT. Verify resistance

change smoothly when throttle closed.