Engine ECU5-126as to avoid damaging electronic control unit.
(1) Simple measuring method:
(Remove joint) turn digital multimeter to ohm position, connect two meter pens with primary winding pinsrespectively, rated resistance at 2 0°C is 0. 4-0. 6 ohm for 2X2 type; on secondary winding, 11-15k ohm for 2x2 type.13. Electronic control unit ECU
Possible cause
Electric overload of externally connected
device leads to burnout of components inside
ECU and results in malfunction Symptom
Unsteady idle speed, poor speedup, failure to start, too high
idle, tail gas overproof, difficult to start, malfunction of air
conditioner, malfunction of fuel injector control, flameout
Repair precautions:
1. Don't remove ECU at discretion during repair;
2. ECU may be removed more than 1 minute after removing storage battery head;
3. Store removed ECU properly;
4. It is prohibited to attach any circuit onto connecting wire of ECU.
Simple measuring method:
1. (Connect joint) use engine data K-line to read engine trouble record;
2. (Remove joint) check whether ECU connecting wire is in good condition or not, mainly check whether ECU
power supply grounded circuit is normal or not;
3. Check whether external sensor works normally, whether output signal is credible, whether circuit is in good
condition;
4. Check whether actuator works normally, whether its circuit is in good condition;
5. Finally replace ECU to conduct test.
Judgment principle: "two interchange principle" ---interchange ECU, interchange fault symptom.III. Diagnostic system Description:
When engine ECU detects a trouble, engine trouble warning lamp on instrument will illuminate. In addition,
relevant diagnostic code will be recorded in ECU memory. Connect handheld tester with diagnostic interface on
automobile, read various data from automobile ECU. Connect handheld tester with diagnostic interface. Technical
personnel may also read fault code via blinking of instrument fault warning lamp.Engine EFI System-
Engine EFI System
No
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
255-128 4. Eliminate fault code either by diagnosis instrument or manually. Manual operation method, specific
procedure: use engine data K-line (namely 9 # terminal of diagnostic interface) earth twice, earthing time is more
than 2. 5 s at each time.
Fault code tableFaulty part
No fault
Electronic control unit (unit) fault
Knocking control zero test
Knocking sensor
Storage battery voltage
Intake pressure sensor
Throttle position sensor
Idle speed control valve
Coolant temperature sensor
Intake temperature sensor
Engine maximum speed overrun
Fuel injector 1
Fuel injector 2
Fuel injector 3
Fuel injector 4
Fan relay
Oxygen sensor
Air fuel ratio control correction coefficient
? self-learning value 1
? self-learning value 2
? self-learning value 3
Fault caution light
Canister control valve
Air conditioner condenser temperature sensor
Phase sensorFault code
11
34
1
15
38
16
14
61
19
18
33
22
23
24
21
42
17
31
35
36
37
45
25
13
43Fault lamp
OFF
ON
OFF
ON
OFF
ON
ON
ON
ON
ON
OFF
ON
ON
ON
ON
ON
ON
OFF
OFF
OFF
OFF
OFF
ON
OFF
ONFault type
-
2
-
2
2
1
1
1
1
1
2
1
1
1
1
1
1
2
2
2
2
1
1
1
1
Fault type: 1-open circuit 2-signal overrun
No. 18 to 21 in the table refers to air fuel ratio correction coefficient,?=actual air quantity/air need for
combustion, "? self-learning value" is also called learning air fuel ratio control value.Engine EFI System-
Engine EFI System
(3) Side Wall Assembly The left/right side wall assembly is a frame structure, which is a side component that connects the front and
rear parts of the body. As shown in Fig.5-4, it includes left/right side wall outside plate assembly, left/right wheel
assembly, left/right A post inside plate assembly, and left/right intermediate post interior plate assembly etc.Survey -Body Structure7-4Fig. 5-4 Side Wall Assembly
1. LH/RH upper front body inner pillar 2.LH/RH lower front body inner pillar 3.LH/RH no.1 crossemember joint panel
4.LH/RH roof inner rail 5.LH/RH center body inner pillar 6.LH/RH rear crossmember tee joint panel
7.LH/RH lower rear pillar remforcement panel 8.LH/RH roof rear inner panel 9.LH/RH side rear pillar inner panel
10.LH/RH luggage compartment support panel 11.LH/RH luggage compartment hinge fixing panel
12.LH/RH wheel house outer panel 13.LH/RH wheel house inner panel 14.LH/RH side panel
15.LH/RH rear combination lamp fixing panel 16.Fuel refilling cap assembly 17.LH/RH side doorsill outer reinforcement panel
18.LH/RH side doorsill inner reinforcement panel 19.LH/RH center pillar upper reinforcement panel
20.LH/RH front seat belt upper reinforcement panel 21.LH/RH roof rail upper master reinforcement panel
22.LH/RH center pillar middle reinforcement panel 23.LH/RH center pillar lower reinforcement panel
24.LH/RH roof rail assistant reinforcement panel 25.LH/RH front body pillar upper reinforcement panel
26.LH/RH front body pillar outer reinforcement panel
