Chery SQR 7160 sedan. Manual - part 128

 

 

Fig 14  Anti-theft ECU 

Anti-theft ECU pin definition 

8-pin connector 

3-pin connector 

1 Not 

used 

1 

Antenna 

positive 

2 

warning indicator 

2 

not used 

3 +30(12V) 

3 

Antenna 

negative 

4 ground 

   

5 Not 

used 

   

6 

to ECU serial surface 

 

 

7 Not 

used 

   

8 

+15 (ignition switch 

positive) 

 

 

  Warning indicator 

Warning indicator on instruments panel is controlled by anti-theft ECU, indicating user 

state information. Warning indicator will flicker under following conditions: 

1.  The key is stored; 

2.  2.5 seconds after the key turned on, the warning indicator begins to flicker, indicating 

system is operating but engine will not be protected until the key is stored. 

5.    Electronic Control Fuel Injection System Maintenance 

        (1) Fuel 

ONLY high quality vehicle unleaded gasoline of RESEARCH RULE octane value 

RON90 or above (conform to SH0041 standard, lead content〈=0.005g/L〉, otherwise, the 

electronic control fuel injection system and 3 way catalyst converter will be damaged, 

affecting exhaust performance.. In addition, sulfur or lead can damage heated oxygen 

sensor. 

        (2) Start-up 

The electronic control fuel injection system can provide appropriate injection fuel width 

under all conditions. Therefore depressing pedal is not necessary before or after hot or cold 

 

start.  

During engine starting, if throttle is at wide open position, injected fuel will reduce a lot, 

which providing a method of cleaning fuel from fuel spilling engine and need not remove 

and wash spark plug. 

It may take a long time to start engine during first starting (new car or after repairing fuel 

system) because fuel pipe need to be charged with appropriate fuel pressure. After repairing 

or refilling fuel again, turn ignition key to ON position and wait for 3 seconds, repeat 

procedures for several times to recover fuel rail pressure.   

3. Stall 

Let engine idle for some time before stalling, which will let engine cool down gradually, 

decrease heat impact strength, and do good for prolong engine operating components and 3 

way catalyst converter life time.      

4.Fuel circulation   

Fuel pressure is up to 3.5 bar, therefore fuel inlet and return circuit must be firmly 

connected and fastened with clamps. 

During checking fuel circuit, starting engine after fuel rail and fuel pipe being removed is 

absolutely forbidden. Otherwise fuel will flow out and may cause fire hazard. Fuel pressure 

must be relieved before removing fuel system components. 

Fuel pressure regulator blockage or fuel return pipe restriction will cause incorrect fuel 

circuit pressure. 

5.Fuel injector 

If vehicle is not driven for a long time, the engine should be started for 3~5 minutes every 

2~3 months to avoid fuel injector blocking. Fuel injectors shall be washed at least every one 

year. Fuel injector O ring is life time component and can not be reused. 

6. 3 way catalyst converter 

When ignition switch is at ON position or engine is under normal operating condition, 

checking firing by removing spark plug or ignition wire is absolutely prohibited. before 

check firing, remove all fuel injector connectors, spark plugs and then connect spark plug to 

corresponding cylinder high-tension wire ensuring spark plug thread part is reliably 

grounded on cylinder body, start engine and check firing. Otherwise catalyst will be 

damaged. 

NOTE: If the engine has been running for a long time, the 3 way catalyst converter will be 

very hot. Do remember to wear protecting glove when servicing to avoid scalding. 

   7. Throttle body 

      Adjustment to anti-stuck screw on throttle valve body by user is forbidden. This screw 

position is precisely adjusted when assembled at factory. Improper adjustment may cause 

high idle speed, engine stalling or idle stability, exhaust and fuel economic performance to 

be affected.   

8. Engine error indicator   

Engine error indicator is located on front instruments panel. When serious error occurs, engine error indicator will 

light. Such case must be repaired by professional person using appropriate tools immediately once occurs.

         

    9. Miscellaneous 

Electric fuel injection system frequent problems are caused by poor contact, therefore al 

connecting points must be clean and have good contact. .ECU is of high quality component, 

and itself seldom has problem. When checking, must use special tool and do not remove and 

 

 

perform unwarranted repairing. 

When ignition is on, DO NOT remove any electrical devices to avoid electric components 

being damaged by inductive electromotive force generated in circuit.   

6.    Electric fuel injection system faults and repairing   

1. Basic knowledge for electric control fuel injection system repairing 

The electric control fuel injection system is a complicated system. Operational person 

should have a good command of system theory, structure, repairing procedures and tester 

using methods. When repairing an engine problem, which may has relation with electric 

fuel injection system, determine if the problem related with electric fuel system first. If 

engine fails and indicator does not light, it is generally not related with electric fuel 

injection system and should be checked and repaired as a carburetion engine.   

When checking and repairing, some instruments and gauges are often used. Frequently used 

instruments and gauge include special scan tester, circuit test light, voltmeter-ohmmeter and 

oscilloscope etc. 

Main methods for checking electronic controlled components includes ohmmeter, voltmeter 

method, scan tester methods etc. Ohmmeter is often used to measure electronic controlled 

components resistance under all conditions. Voltmeter is often used to measure electronic 

controlled components voltage under all conditions and scan tester is used to determine if an 

electronic controlled component operative upon indicated value on display (such as 

monitoring coolant temperature sensor, air intake temperature pressure etc.) 

          2. Electric control fuel injection system problem diagnostic precaution 

(1) No matter engine is running or not, when ignition is on, any electrical units absolutely 

CAN NOT be removed, such as any battery lead, idle control valve, fuel injector, electric 

fuel pump, ignition system cable, ECU circuit, A/C circuit.         

        (2) When checking ignition circuit, fuel pipe and electrical circuit to be tested must be 

disconnected before starting engine. Disconnecting ignition wire is absolutely forbidden 

when engine is running.   

    (3) Ohmmeter and indicator used to check sensor and electric controller resistance 

must be over than 10kΩ, otherwise sensor and ECU may be damaged.   

(4) ECU is a high quality integrated circuit, the failure ratio is very low, and do not suspect 

its failure. 

(5) Preventing water splashing to system wiring harness and sensor which will cause short. 

(6) Before welding vehicle circuit, removing battery negative terminal. 

(7) Electrical arch welding operating must be far away from ECU and sensor 

        3. Electric control fuel system fault and repairing 

(1) Engine does not start or hard to start 

 

 

 

 

 

 

 

 

 

 

No Problem 

causes 

 

Actions 

1. 

Fuel injector fault 

check if fuel injector operating condition 

normal using scan tester.   

2 

Crankshaft speed and position sensor 

fault 

Using feeler gauge, check clearance 

crankshaft speed and position sensor head 

and signal wheel tooth top. Check sensor 

circuit. 

3 

ECU socket fault 

Check if good contact between socket and 

ECU. 

4 

Idle speed control valvel fault   

Using scan tester, check idle speed control 

valve operating condition, and inspect if 

connector contact is good. 

5 

Loosen  throttle valve body mounting 

screw 

Tighten throttle valve body mounting 

screw 

 

(2)  Insufficient engine power   

No. Problem 

Causes 

Actions 

1 

Poor electric fuel pump operation

Check if all connections good. Check electric fuel 

pump, replace as necessary. 

2 

Blocked fuel filter or pipe 

Check if fuel filter and fuel pipe blocked, clean or 

replace fuel pipe as necessary.   

Insufficient or unstable fuel feed 

pressure 

Check fuel circuit and electric fuel pump. 

Check if fuel injection pressure is within 

specification. 

Insufficient air intake   

Check air intake pipe 

3 

Damaged fuel injector 

Check fuel injector performance data and 

injection hole, replace as necessary 

Damaged air intake pressure 

sensor 

Check air intake pressure sensor performance 

data, replace as necessary. 

Damaged crankshaft speed and 

position sensor 

Check crankshaft speed and position sensor 

performance data, replace as necessary/ 

Damaged throttle position sensor

Check throttle position sensor performance data, 

replace as necessary. 

3 

Optimum ignition time not 

reached 

Replace ECU