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  #1  
Old 03-14-2003, 08:18 PM
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Join Date: Mar 2003
Location: tn
Posts: 41
190e idle control current draw

Still working on high idle speed. voltage to the idle control starts out cold near zero and builds up as the engine warms up. however there is no current flow! the device works when i put voltage directly to it. what am i missing? also there is what appears to be a vacuum switch behind the battery with 3 wires going to it but no vacuum line. part no. 006 542 50 10. anyone know what it is used for. i'm grasping at straws now!
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  #2  
Old 03-14-2003, 09:52 PM
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Join Date: Sep 2002
Location: lynchburg, va.
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The device behind battery is the altitude correction capsule.
But there should be four wires, pin #2 should have two wires.
Pin #1 goes to ECU plug terminal #14(blu/red)
Pin # 2 goes to air flow position indicator pin #3(blu/gn)
2 goest to ECU terminal #18(blu/gn)
Pin# 3 goes to air flow positon indicator pin # 1(brw/wht)
With the ignition on, or with the engine running the capsule
will receive a constant voltage approx 5V from the ECU .
If ECU operates in a fix mode, correction for altitude will not
take place. Measurments are made between term #1 & #3.
and they shoul be as follows;
0 m above sea level, baromatric pressure 1013 mbar, 4V+/-1V
1000m, bar pressure 899mbar, 3V+/-1V
2000m, bar pressure 795mbar, 2V+/-1V
What year is your 190 and what engine does it have?
Wher are you trying to measure the voltage at?
Give me more info!.

Last edited by kjsabat; 03-14-2003 at 10:22 PM.
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  #3  
Old 03-15-2003, 01:02 AM
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should the altitude device have a vacuum hose connected? from where? voltage checked across idle control connector. current checked with one connector pin connected and dvm from the other pin to the other connector plug. any ideas???
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  #4  
Old 03-15-2003, 01:13 AM
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my car is a 1988 190 e 2.3 thanks for your response!
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  #5  
Old 03-15-2003, 02:24 AM
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Location: lynchburg, va.
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The altitude correction capsule has no vacuum line attached to it.
It supposed to read a barometric pressure and send proper signal
to ECU. With increasing altitude, decreasing air pressure, the mixture will be adapted to the altitude by a reduction of the voltage. I am still not in the clear what are you trying to do!
Are you checking voltage at air flow position sensor, or are you checking current at EHA?
I assume your 190 has 8 valve engine.
For 8 valve engine static current at EHA approx 20mA.
To check static current turn egnition key on, engine off. Unplug coolant temp sensor. Pull plug from the EHA just a little bit, enough to get to pins. Plug must be connected to EHA. Set your multimeter to mA. Measure current between pins.
Since you will be working with EHA you need to check the resistance of EHA as well. Turn egnition off. Disconnect plug from EHA. Set your multimeter to Ohms. Measure resistance between pins, it should be 19.5 +/- 1.5Ohms. If the resistance is different then specified, you need to replace EHA.
Now! I sort of jump to a middle of the procedure of testing CIS-E.
There are many test steps preceding the above tests.
To completly evaluate the performance of CIS you need to start at the begining. Let me know what is the problem with your engine, and what are you trying to accomplish.
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  #6  
Old 03-15-2003, 07:16 AM
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Join Date: Mar 2003
Location: tn
Posts: 41
my basic problem is fast idle when warm. i have checked the eha, the ovp relay, replaced all associated hoses, soaked the idle control overnight and lubed with wd40. as best i can tell the rotary idle control never moves. i connected 12v directly to it and the engine raced. the voltage at the connector rises as the engine warms but no current flows. i only asked about the altitude thing because i didn't know what it was . do i have a computer problem or is there something else in the curcuit i need to check? thans for your input!
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  #7  
Old 03-15-2003, 09:50 AM
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Location: lynchburg, va.
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O.K. so you are working with Idle Speed Air Valve! Perform the following test. Igniton on, engine off. Disconnect plug from idle
speed air valve. Connect battery voltage to idle speed air valve.
The valve should switch audibly. This can also be felt. If you do not feel and hear the valve working, replace the idle air speed valve. If it works OK, test voltage supply between plug's terminal #2 of the idle valve and ground. It should be approx battery voltage. If there is no voltage, disconnect battery, disconnect plug from ECU and test for continuity between plug terminal #1 of idle valve and terminal # 3 of ECU plug. If there is no continuity repair open circuit. If there is connection, you will need to perform more tests. Also test for continuity between plug's pin #2 of air valve and pin #2 of OVP relay. Let me know what you find out. I know I am repeating some of the work you have already done, but I want others to follow the procedure when they need it.

Last edited by kjsabat; 03-15-2003 at 12:11 PM.
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  #8  
Old 03-15-2003, 10:02 AM
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Location: SoCal
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Are you checking the voltage atn the idle control valve with the connector attached? The readings will be meaningless without the connector attached, because there is no load on the ECU output. If the connector IS attached, then then the valve will draw current, if it shows a static resistance.

Steve
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  #9  
Old 03-15-2003, 10:40 AM
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i was checking voltage between the two pins with the connector disconnected and the engine running. i was checking current with one side of the connector on and my dvm between the other side of the connector and the other idle control pin. thanks to both of you for the info. i'll go check the other stuff now. i think this has become an obsession!
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  #10  
Old 03-15-2003, 11:51 AM
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eha static current 19.72. eha resistance 18.5 ohms. battery voltage to idle speed valve clicks. temr 2 to gound not battery voltage. this voltage seems to rise as temp rises when engine is running. less than 1 ohm between #1 idle valve and term 3 of ecu. same for pin#2 andpin#2 of ovp relay. is the fact that the voltage rises with temp trying to tell me something??? help!
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  #11  
Old 03-15-2003, 11:55 AM
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Location: lynchburg, va.
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The MB test procedure is very strickt and must be followed step by step. You do not need to check current draw by idle speed air
valve. Just follow the procedure step by step and give me the feedback. It could be that your idle speed control valve is OK, but is not working because the ECU is operating in a fix mode. Most likely the ECU does not receive input from one of the following components; coolant temp sensor, air flow position sensor, throttle valve switch, OVP and O2 sensor. All of the components must be tested according to MB procedure before you start to replacing components. Otherwise it will be simply a very expansive guess work. Also before you start to play with Lambda setting, performance of all of the components must be evaluated according to MB procedure, including fuel pressure, and performance of fuel injectors. You have to be very methodical with it. Otherwise the whole work is nothing more then pissing in the wind.
Also, explain what DVM means. I can not find DVM in MB manual.
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  #12  
Old 03-15-2003, 12:06 PM
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Location: lynchburg, va.
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I think you were testing voltage between pin @2 of idle speed valve and the ground. The voltage should be tested between plug's pin #2 and the ground and it should be constant( approx 12V). Engine not running, ignition on. Give me your feedback.

Last edited by kjsabat; 03-15-2003 at 12:15 PM.
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  #13  
Old 03-15-2003, 08:12 PM
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Join Date: Oct 2002
Location: Toronto, Canada
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I think the dvm here stands for Digital Volt Meter, am I right?

Great post though, I think I will follow it just to see what I get and give some feedback to everyone.

xp
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  #14  
Old 03-15-2003, 09:30 PM
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Join Date: Mar 2003
Location: tn
Posts: 41
DVM is digital voltmeter. MAJOR PROBLEM SOLVED!! minor ones remain. THANKS for EVERYONES HELP! voltage at pin 2 of idle speed control was much lower than battery voltage and increased with heat due to a cold solder joint inside the ovp relay. i removed the cover, found the bad connection re-soldered and re-sealed and idle is working GREAT! x-11 pin 3 duty cycle cold is about 18 percent, as it warms up some sensor kicks in and it goes to 48/52 percent then later something else happens and it rises slowly and stops at 80 percent and stays there. if i open throttle to about 2000 rpms and back it drops back to 48/52 then goes back up to 80 percent. oxygen sensor voltage from gound to black wire is constant at .220v. after engine is warm. is this a problem or should i just quit complaining and drive the car?
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  #15  
Old 03-17-2003, 11:45 PM
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Location: lynchburg, va.
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The O2 sensor must be tested with the engine in oprating temperature. Disconnect O2 sensor plug. O2 sensor pulg is located inside car, under floormat, near passenger seat. Disconnect O2 sensor plug and connect male part to ground. Start engine, test sensor voltage between female part of plug and ground. Sensor voltage must be above 450 mV. If not, replace O2 sensor. Test for continuity between male part of plug and ECU plug term #8. Repair interruption if necessary.
Test O2 sensor heater. Engine shut off. Loosen plug of O2 sensor to allow voltage testing. Pull off fuel pump relay and jump terminal 7&8. Reading, battery voltage, OK. Not battery voltage. Repair interruption. Unplug O2 sensor heater plug. Connect test cable 102 589 04 63 00) with adapter plug 903 589 03 63 00. Test current draw. Above 0.5A OK. End of test. Not OK, replace O2 sensor, repeat the procedure. You can make your own test cable from parts available at Radio Shack. Also if you decide to use other then MB oxygen sensor. Make sure it meets the MB spec.
Use "Search" to find out what vehicle's O2 sensor can be used as possible sub for MB O2 sensor.

Last edited by kjsabat; 03-17-2003 at 11:51 PM.
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