In the automotive braking, if the wheels from locking slip, lateral adhesion between the wheels and the road will completely disappear. If only the front wheel (steering wheel) brake to lock the rear wheels slip while still rolling, the car will lose steering ability. If only the rear brake to lock the front wheels slip while still rolling, even by small lateral disturbance force, the car will also have a slip (drift) phenomenon. These are easily cause a serious accident. Therefore, you do not want the car when braking wheel brake to lock slip Autel MaxiCheck Airbag ABS SRS Light Service Reset Tool, but hope to edge trim wheel brake slip state.
By experiment that, car wheel slip rate at 15% to 20%, between the tire and the road surface friction coefficient has the largest. So in order to give full play to the ability of this potential adhesion between tire and road, currently on most vehicles are equipped with anti-lock braking system (AntilockBrakeSystem), referred to as ABS . our shop supply Autel MaxiCheck Airbag ABS SRS Light Service Reset Tool
ABS composition and working principle
Typically, ABS wheel speed sensor is the installation of the braking system on the basis of the ordinary, ABS electronic control unit, brake pressure regulating device and other components of the brake control circuit.
During braking, ABS electronic control unit (ECU) 3 continuously obtained from the wheel speed sensor 1 and the signal 5, and processed, to analyze whether there is a wheel is about to lock the slide drag.
If no trailer wheel slip is about to lock, the brake pressure regulating means 2 is not involved in the work, the brake master cylinder of the brake cylinders 7 and 9 in communication, the brake wheel cylinder pressure continues to increase, namely, ABS braking process the pressurized state.
If the electronic control unit determines that the individual wheels (assumed to be a left front wheel) is about to drag the locking slide, namely a brake pressure regulating means which issues a command to close the left front brake master cylinder and the wheel brake cylinder passages and the front left system wheel cylinder pressure no longer increases, namely ABS braking process of packing state.
If the electronic control unit determines that the locking of the left front wheel tends to drag the slider still state, namely it issues a command brake pressure regulating means, to open the left front wheel brake cylinder and the reservoir chamber or the accumulator (not shown) the channel, so that the left front wheel cylinder braking oil pressure decreases, namely, the pressure during ABS braking condition.
ABS hydraulic control assembly structure ,to buy Autel MaxiCheck Airbag ABS SRS Light Service Reset Tool visit our shop www.obd2works.com
ABS hydraulic control assembly is in the hydraulic unit on the basis of ordinary braking system designed after the installation of ABS brake pressure regulator formed.
Hydraulics ordinary braking system generally includes brake booster, brake master cylinder, double chamber, reservoir chamber, brake wheel cylinder and dual hydraulic lines and so on. In addition to the hydraulic braking system outside an ordinary member, ABS brake pressure regulator usually consists of an electric pump, the accumulator, the main control valve, the solenoid control valve and some control switches and other components. Essentially, ABS system is controlled by a hydraulic control valve solenoid on the valve body Cylinder quickly becomes larger or smaller, in order to achieve the anti-lock braking function.
(1) electric pump
The electric pump is a high pressure pump, which can be pressurized brake fluid in a short time (in the storage vessel) to 15 ~ 18MPa, and the entire hydraulic brake system provides a high pressure liquid. Electric pump can be started in the car to complete the work within one minute. Electric pump operates independently of the ABS computer, computer failure or wiring if there is a problem, the electric pump can still work.
(2) the accumulator
Diverse forms of energy storage structure. Autel MaxiCheck Airbag ABS SRS Light Service Reset Tool used more as a piston - spring-accumulator, the accumulator located between the solenoid valve and back to the pump, the wheel cylinder to the hydraulic fluid into the accumulator, thereby compressing the spring so that the hydraulic accumulator cavity volume change large to temporarily store the brake fluid.
(3) solenoid control valve
The electromagnetic control valve is an important component of the hydraulic actuator, it is done by the control of the ABS. ABS systems have one or two solenoid valve, which has a plurality of solenoid-controlled valve, the front and rear wheels, respectively, brake control. There are three commonly used three-way solenoid valves and two two-way valves and other forms.
(4) pressure control, pressure and level warning indicator switch
Pressure control switch (PCS) working independently of the ABS computer, monitoring the pressure of the lower chamber of the accumulator. Pressure Alarm Switch (PWS) and level indicator switch (FLI) function is, when the pressure drops to a certain value (14MPa or less) or when braking level drops to a certain extent, the fault indicator lights and ABS braking system fault indicator, while allowing the ABS anti-lock brake computer stops working.
Showing posts with label ECU. Show all posts
Showing posts with label ECU. Show all posts
Monday, August 4, 2014
Thursday, July 17, 2014
How To Repair your ECU
Someone great once said, “Necessity is the mother of all invention” (Plato). Well, I don’t claim to be Plato, but I do have the High Honors of possessing “Necessity”. That brings me to my point.
While Dad and I were working on this 1988 YJ project, we developed “necessity”. The Jeep was purchased with a suspect computer and wiring problem and in a non running condition. An eBay Wiring harness and ECU made short work of that “no run state” and the project rolled on.
I would like to share what I found and what was done to REPAIR the ECU chip tuning. If only one person can gain from this experience, I would feel like our blessing could be passed along to another in need.
First the basics: 1989 YJ, 2.5 4 Cylinder, Throttle Body Injection, Manual 5 speed.
Failure Symptoms: Fuel Pump Runs continuously with key turned from Off to ON position, No Spark, No Fuel Pulse at TB Injector.
ECU’s - common Part No. EF8953005023 (and the Renix 9-2099)
Renix (Remanufactured; original unit in Jeep, a non running purchase)
Bendix (eBay + Harness, worked when installed. Until…)
Siemens X2, (eBay purchase, seller sent two “just in case”. Both NOGO)
And I suppose a disclaimer is needed for those fool hearty enough not to realize if all goes well, they will be repairing a component that in not supposed to be repairable. Follow These Directions At your Own Risk; I am not responsible for what you do to your Jeep. …sorry
Early in the troubleshooting process I became fully convinced that the ECU was the point of failure. I eventually wound up having 4 ECU’s in hand and with nothing else to loose, coupled with the fact of being too stubborn to pay retail for a New Computer just to put it in and possibly toast it, (read no return on electrical parts) I had to go with my gut and crack them open.
Tools needed for the job:
TORX 10 & 20
Soldering Tool & Resin Core Solder (de-soldering may be necessary)
Patience
Here we are set up for the job…
The ECU is removed from the mounting bracket and the back cover is removed. The cover is held on by four Torx 10 screws. What I found in all cases was a heat damaged printed circuit board and or a diode.
This picture shows one board with a damaged Trace, the connection between Pin 3 on the main connector and the diode at position D35. Second picture marked for clarity.
A Multi-Meter set to Ohm’s can confirm no continuity resulting in an open trace.
This can also be performed easier from the bottom of the board.
To remove board from housing, remove the 4 - torx 10 at red circles and 1- Torx 20 at green circle. Lift board carefully from opposite side of main connector, do not bend PCB. (Poor picture sorry)
This is a picture of a damaged diode. Picture taken after de-soldering from ECU. This metered a value of .492 and was BAD, another was metered “open”, also bad.
This is a GOOD diode, meter value at 1.522 and another measured the same, these were the two boards I repaired.
The Renix remanufactured unit had a Heavy Duty looking diode installed when it was remanufactured, who knows when. I quickly realized that if the printed circuit was restored, it was highly likely that all would be good! Time to repair the open trace.
Carefully make a jumper wire from your choice stock, CAT5 in my case; this will be used to restore the open circuit.
Lay it in and size it up to fit before soldering. Double check that you are making the correct connections!
Here is the Jumper after being soldered to correct pins.
A covering of Hot Glue provides both insulation and protection.
And lastly a quick check to verify operation. If you’ve made it this far, I hope you are as blessed as we were! Running Jeep, Priceless!
After testing, the unit was remounted into the outer case and reinstalled into the Jeep.
Final testing and “The Payoff”, Road Trip… (Ahh, life is good!) “Dad in his Jeep YJ”
Two ECU’s repaired - the fix; using the repaired Trace method. I will be looking for replacement diodes to mount into the two remaining ECU’s. I am confident that this will resolve their conditions as well.
I am also pretty certain that the weak connection or no connection at the starter relay main lug and the fusible links were the contributing factors in this particular failure. These were also completely redone while waiting for the mailman. Note: Pin 3 on the main ECU connector is identified in the FSM as Starter Switch.our shop: www.obd2works.com
While Dad and I were working on this 1988 YJ project, we developed “necessity”. The Jeep was purchased with a suspect computer and wiring problem and in a non running condition. An eBay Wiring harness and ECU made short work of that “no run state” and the project rolled on.
I would like to share what I found and what was done to REPAIR the ECU chip tuning. If only one person can gain from this experience, I would feel like our blessing could be passed along to another in need.
First the basics: 1989 YJ, 2.5 4 Cylinder, Throttle Body Injection, Manual 5 speed.
Failure Symptoms: Fuel Pump Runs continuously with key turned from Off to ON position, No Spark, No Fuel Pulse at TB Injector.
ECU’s - common Part No. EF8953005023 (and the Renix 9-2099)
Renix (Remanufactured; original unit in Jeep, a non running purchase)
Bendix (eBay + Harness, worked when installed. Until…)
Siemens X2, (eBay purchase, seller sent two “just in case”. Both NOGO)
And I suppose a disclaimer is needed for those fool hearty enough not to realize if all goes well, they will be repairing a component that in not supposed to be repairable. Follow These Directions At your Own Risk; I am not responsible for what you do to your Jeep. …sorry
Early in the troubleshooting process I became fully convinced that the ECU was the point of failure. I eventually wound up having 4 ECU’s in hand and with nothing else to loose, coupled with the fact of being too stubborn to pay retail for a New Computer just to put it in and possibly toast it, (read no return on electrical parts) I had to go with my gut and crack them open.
Tools needed for the job:
TORX 10 & 20
Soldering Tool & Resin Core Solder (de-soldering may be necessary)
Patience
Here we are set up for the job…
The ECU is removed from the mounting bracket and the back cover is removed. The cover is held on by four Torx 10 screws. What I found in all cases was a heat damaged printed circuit board and or a diode.
This picture shows one board with a damaged Trace, the connection between Pin 3 on the main connector and the diode at position D35. Second picture marked for clarity.
A Multi-Meter set to Ohm’s can confirm no continuity resulting in an open trace.
This can also be performed easier from the bottom of the board.
To remove board from housing, remove the 4 - torx 10 at red circles and 1- Torx 20 at green circle. Lift board carefully from opposite side of main connector, do not bend PCB. (Poor picture sorry)
This is a picture of a damaged diode. Picture taken after de-soldering from ECU. This metered a value of .492 and was BAD, another was metered “open”, also bad.
This is a GOOD diode, meter value at 1.522 and another measured the same, these were the two boards I repaired.
The Renix remanufactured unit had a Heavy Duty looking diode installed when it was remanufactured, who knows when. I quickly realized that if the printed circuit was restored, it was highly likely that all would be good! Time to repair the open trace.
Carefully make a jumper wire from your choice stock, CAT5 in my case; this will be used to restore the open circuit.
Lay it in and size it up to fit before soldering. Double check that you are making the correct connections!
Here is the Jumper after being soldered to correct pins.
A covering of Hot Glue provides both insulation and protection.
And lastly a quick check to verify operation. If you’ve made it this far, I hope you are as blessed as we were! Running Jeep, Priceless!
After testing, the unit was remounted into the outer case and reinstalled into the Jeep.
Final testing and “The Payoff”, Road Trip… (Ahh, life is good!) “Dad in his Jeep YJ”
Two ECU’s repaired - the fix; using the repaired Trace method. I will be looking for replacement diodes to mount into the two remaining ECU’s. I am confident that this will resolve their conditions as well.
I am also pretty certain that the weak connection or no connection at the starter relay main lug and the fusible links were the contributing factors in this particular failure. These were also completely redone while waiting for the mailman. Note: Pin 3 on the main ECU connector is identified in the FSM as Starter Switch.our shop: www.obd2works.com
Wednesday, June 25, 2014
Attention when use the easydiag
The easydiag android app you can download on google app store:https://play.google.com/store/apps/details?id=com.cnlaunch.EasyDiag&hl=en
EasyDiag is a portable and economy vehicle trouble diagnostic device developed by Launch for vehicle maintenance technician.
Precautions on operating vehicle’s ECU
Do not disconnect the vehicle inner consume when the ignition switch is on, so as to avoid the sensors or the ECU damage. Do not place the magnetic object near the ECU in order to avoid the failure of the circuitry and components. Do cut off the
power supply of ECU system before welding on the vehicle. Pay more attention to the ECU and the sensors when the operation is next to them. Ground yourself when you disassemble PROM, otherwise ECU and sensors will be damaged by static
electricity. Do connect ECU harness connector firmly, otherwise electronic elements, such as IC inside ECU, will be damaged.
Precautions on operation
The instrument is a precision electronic instrument. Pay more attention when in use, do not have it dashed.
The equipment power is supplied by 12v battery voltage; do not use other voltage power.
Turn off the ignition switch when connect or disconnect the diagnostic connector.
Do not keep EasyDiag Pin Connector plugged into your vehicle overnight, be sure to always remove connector once testing and/or diagnosis is complete. Failure to do so may result in drained or weakened battery
EasyDiag, based on iOS/Android operation system design, research and development, is an internet vehicle trouble diagnosis tester customized for mobile intelligent trminals. After being connected with mobile terminal through Bluetooth, it achieves for LAUNCH Diagnostic Tool serial product the full diagnostic functions, which include reading DTCs(diagnosis trouble code), clearing DTCs, reading data stream, action test and special functions，Meanwhile, through your intelligent mobile terminal, you can access internet to get your demanded information, share and exchange information, etc
Note: before operating, you need to log in software first.
If your Android phone’s Bluetooth is closed, a request as Fig4.1 will be seen once open the software,Select “yes” to turn on Bluetooth, or you can not communicate with EasyDiag After selection, you will see some illustrations; glance down these
illustrations by sliding the screen to left can make you have a general understanding for the use of the software. The next step, you will see the disclaimer which contains some precautions and warnings about using, please read it carefully.
When reading is finished, click “I’ve read it” to enter login interface, see Fig4.3. If you don’t want to read this again, choose “Don’t show this again”; the disclaimer will not appear next time. Please login before starting to operate. Click “Login” to open login
interface.
EasyDiag is a portable and economy vehicle trouble diagnostic device developed by Launch for vehicle maintenance technician.
Precautions on operating vehicle’s ECU
Do not disconnect the vehicle inner consume when the ignition switch is on, so as to avoid the sensors or the ECU damage. Do not place the magnetic object near the ECU in order to avoid the failure of the circuitry and components. Do cut off the
power supply of ECU system before welding on the vehicle. Pay more attention to the ECU and the sensors when the operation is next to them. Ground yourself when you disassemble PROM, otherwise ECU and sensors will be damaged by static
electricity. Do connect ECU harness connector firmly, otherwise electronic elements, such as IC inside ECU, will be damaged.
Precautions on operation
The instrument is a precision electronic instrument. Pay more attention when in use, do not have it dashed.
The equipment power is supplied by 12v battery voltage; do not use other voltage power.
Turn off the ignition switch when connect or disconnect the diagnostic connector.
Do not keep EasyDiag Pin Connector plugged into your vehicle overnight, be sure to always remove connector once testing and/or diagnosis is complete. Failure to do so may result in drained or weakened battery
EasyDiag, based on iOS/Android operation system design, research and development, is an internet vehicle trouble diagnosis tester customized for mobile intelligent trminals. After being connected with mobile terminal through Bluetooth, it achieves for LAUNCH Diagnostic Tool serial product the full diagnostic functions, which include reading DTCs(diagnosis trouble code), clearing DTCs, reading data stream, action test and special functions，Meanwhile, through your intelligent mobile terminal, you can access internet to get your demanded information, share and exchange information, etc
Note: before operating, you need to log in software first.
If your Android phone’s Bluetooth is closed, a request as Fig4.1 will be seen once open the software,Select “yes” to turn on Bluetooth, or you can not communicate with EasyDiag After selection, you will see some illustrations; glance down these
illustrations by sliding the screen to left can make you have a general understanding for the use of the software. The next step, you will see the disclaimer which contains some precautions and warnings about using, please read it carefully.
When reading is finished, click “I’ve read it” to enter login interface, see Fig4.3. If you don’t want to read this again, choose “Don’t show this again”; the disclaimer will not appear next time. Please login before starting to operate. Click “Login” to open login
interface.
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