DELPHI electronic control system troubleshooting , and repair Wang talks about the electronic control system for your general troubleshooting steps and , obviously intermittent troubleshooting procedures and other methods , in the hope that more owners and repair technicians help.
Tools / materials : DELPHI DS150E electronic control system
Wang automotive diagnostic repair
Methods / steps: general troubleshooting steps are as follows
( 1 ) diagnostic content.
( 2 ) to confirm customer complaints or symptoms.
( 3 ) the ignition switch to "ON", but do not start the engine , the engine malfunction indicator light is observed.
( 4 ) Check that the engine malfunction indicator lamp circuit is normal.
( 5 ) Use 431ME normal display diagnostic information to confirm whether the engine control unit.
( 6 ) Start the engine and observe whether the normal engine start.
( 7 ) Are there any fault codes.
( 8 ) Wang diagnostic Comparison repair data stream on the display measured value of the reference engine diagnostic data , measured values are observed in the normal range.
( 9 ) one by one to check and confirm the fault code.
( 10 ) Check the wiring associated components are normal.
Clear fault code , confirm whether the repair is completed.
Intermittent obvious troubleshooting procedures
For obvious intermittent failure problem, follow these steps to check the following example :
An initial inspection
Before performing this step is necessary to complete the general troubleshooting procedures. After careful observation , and can correct problems found to reduce the time required for troubleshooting . Initial inspection order as follows:
( 1 ) confirm the engine control unit assembly Ground area clean and proper locking .
( 2 ) Check the vacuum tubes and joints , cracks or loose and cause leaks due .
( 3 ) Check the throttle body or air inlet leaks.
( 4 ) Check the spark plug high voltage coil seated , make sure no cracks or broken wires , and remove spark plug fouling .
( 5 ) Verify that all circuit terminals and connecting wires are connected properly.
2, according to the troubleshooting process checks
Use the troubleshooting flow chart for a thorough inspection , replacement parts do not necessarily need to deal with the problem .
3 circuit connection failure
Most intermittent faults are caused by poor contact in the circuit , should be carefully examined following the suspected lines:
① leads to poor contact ; ② does not touch the terminal section (Figure 18-6); ③ terminal damage ; ④ terminals and circuit loose.
4 , road test
If based on experience and careful measurement and inspection , has yet to find the cause of the fault , the road should be real vehicle detection , and also part of the circuit using a voltmeter for measurement of the suspected or use 431ME diagnostic tests read fault with the real vehicle information, when the line after checking and fault code storage .
5 , intermittent engine fault indicator shows
Intermittent engine fault indicator light, but no fault code , it may be for the following reasons :
① The engine control unit (ECM) poor grounding .
② the relay does not operate normally , the engine control unit (ECM) or a solenoid driven switch , the electronic system caused by dry excellent.
③ inappropriate choice of electrical installations , including lighting, change radio channels , music system or alarm systems.
④ spark plug ignition control circuit wiring should be in order to check the ignition system to the generator , and engine control unit (ECM) to a low-voltage circuit of the ignition system should have a good grounding .
⑤ secondary ignition side short to ground .
⑥ engine fault indicator or diagnostic test terminal generates an intermittent short circuit.
6, the fuel system
Some intermittent failure may be due to poor quality of fuel produced , when the real vehicle test if sometimes suddenly stalled or other failure occurs , please check whether the customer has to buy gasoline following circumstances :
( 1 ) whether they have the same gas station ? If yes, could be fuel quality problems.
( 2 ) whether the gas station to buy cheaper oil ? If it is , you need to check whether the tank sediment , water or other impurities.
Tools / materials : DELPHI DS150E electronic control system
Wang automotive diagnostic repair
Methods / steps: general troubleshooting steps are as follows
( 1 ) diagnostic content.
( 2 ) to confirm customer complaints or symptoms.
( 3 ) the ignition switch to "ON", but do not start the engine , the engine malfunction indicator light is observed.
( 4 ) Check that the engine malfunction indicator lamp circuit is normal.
( 5 ) Use 431ME normal display diagnostic information to confirm whether the engine control unit.
( 6 ) Start the engine and observe whether the normal engine start.
( 7 ) Are there any fault codes.
( 8 ) Wang diagnostic Comparison repair data stream on the display measured value of the reference engine diagnostic data , measured values are observed in the normal range.
( 9 ) one by one to check and confirm the fault code.
( 10 ) Check the wiring associated components are normal.
Clear fault code , confirm whether the repair is completed.
Intermittent obvious troubleshooting procedures
For obvious intermittent failure problem, follow these steps to check the following example :
An initial inspection
Before performing this step is necessary to complete the general troubleshooting procedures. After careful observation , and can correct problems found to reduce the time required for troubleshooting . Initial inspection order as follows:
( 1 ) confirm the engine control unit assembly Ground area clean and proper locking .
( 2 ) Check the vacuum tubes and joints , cracks or loose and cause leaks due .
( 3 ) Check the throttle body or air inlet leaks.
( 4 ) Check the spark plug high voltage coil seated , make sure no cracks or broken wires , and remove spark plug fouling .
( 5 ) Verify that all circuit terminals and connecting wires are connected properly.
2, according to the troubleshooting process checks
Use the troubleshooting flow chart for a thorough inspection , replacement parts do not necessarily need to deal with the problem .
3 circuit connection failure
Most intermittent faults are caused by poor contact in the circuit , should be carefully examined following the suspected lines:
① leads to poor contact ; ② does not touch the terminal section (Figure 18-6); ③ terminal damage ; ④ terminals and circuit loose.
4 , road test
If based on experience and careful measurement and inspection , has yet to find the cause of the fault , the road should be real vehicle detection , and also part of the circuit using a voltmeter for measurement of the suspected or use 431ME diagnostic tests read fault with the real vehicle information, when the line after checking and fault code storage .
5 , intermittent engine fault indicator shows
Intermittent engine fault indicator light, but no fault code , it may be for the following reasons :
① The engine control unit (ECM) poor grounding .
② the relay does not operate normally , the engine control unit (ECM) or a solenoid driven switch , the electronic system caused by dry excellent.
③ inappropriate choice of electrical installations , including lighting, change radio channels , music system or alarm systems.
④ spark plug ignition control circuit wiring should be in order to check the ignition system to the generator , and engine control unit (ECM) to a low-voltage circuit of the ignition system should have a good grounding .
⑤ secondary ignition side short to ground .
⑥ engine fault indicator or diagnostic test terminal generates an intermittent short circuit.
6, the fuel system
Some intermittent failure may be due to poor quality of fuel produced , when the real vehicle test if sometimes suddenly stalled or other failure occurs , please check whether the customer has to buy gasoline following circumstances :
( 1 ) whether they have the same gas station ? If yes, could be fuel quality problems.
( 2 ) whether the gas station to buy cheaper oil ? If it is , you need to check whether the tank sediment , water or other impurities.