ECM Ground & 5 Volt Interactive Wiring Testing, using the interactive wiring diagram system. See how it's dome using a 20 OHM resistor and how to stress the circuit for testing.
Mandy is a genius. Have read 4 of his books got 5 more coming. As an old tech from the late 70 -80s Iam trying to learn as much as possible. Even though now only fix my subdivision and church members cars for free . It’s my retirement but the new systems are confusing. So far my base knowledge gets me through
This explans why i have a different ground to the battery ground on all my engine sensors, the imrc also has a different 12volt and ground supply aswell, the imrc is an actuator with active electronics inside attached to the engine, the imrc contains its own micro controller which is always listening to the ecm so the imrc must need clear power and uninterrupted data communication to the ecm
Wow. This is super helpful. First I didn’t know that the sensor grounds were filtered through the ECM. So testing signals relative to chassis gnd (like I was) doesn’t give an accurate result. And I didn’t know about testing the +5 and ecm gnd with a load. I do have a loadpro that has 25 ohm, but you suggested 20. Would the 25 be safe? Thanks!
Ok, a few things about the. Running about 2 Amps through the circuit is the most reliable way. I developed 2 Testing Units that do that. The STRESS Loaded Testlight and the OBD-II DLC Health Checker. It's too much to detal here, so click these links below, thanks. www.autodiagnosticsandpublishing.com/Stress_Loaded_Tester.html www.autodiagnosticsandpublishing.com/OBD_2_DLC_Health_Checker.html
@@ADPTraining Thanks but if that's the case I would follow your own suggestion and use a 20 ohm resistor, for pennies. My question though was whether the LoadPro would work for his test and I presume the answer is yes.Your information in helpful but I'm not interested in your $145 loading device and you (understandably) keep circling back to that, which is disappointing.
i just had massive electrical weirdness from a FAULTY/SHORTED crankposition sensor..........it was NEW. Cheap @ $13 vs the proper $55 AC DELCO version. But messed things up........... fuel gauge going crazy, ignition coil zapping away, other solenoids clicking away. I had put in a new ECU also- and trying to do a 30 min key relearn in order to start. But the above fouled things up UNTIL I just swapped the old, good CKP sensor back in. Crazy!
@@ADPTraining thanks. The problems only began after I did a hard restart/clear of the ECU (touching the battery cables together for a few mins): which I was doing to sort out a CKP relearn. And a lingering P0300 random misfire issue. Leaving the key ON for the 30min security key relearn process in when the above began. (and I had installed a new BAD CKP sensor at this time also). I hope to sort this out soon. Thanks!
@@ADPTraining it turns it the bad CKP sensor was the issue........ and after figuring out how to properly do the KEY RELEARN (from the new ECU) the van started. All good. KEY RELEARN: I was turning the key all the way (off) then back to ON postion- vs simply moving off from CRANKING position to ON. (passkey security system). The bad (NEW: $13) CKP sensor was replaced w a proper AC DELCO caliber unit. Cheers!
We make our own. It is more a program and we need about 5 days to make after order. www.autodiagnosticsandpublishing.com/Automotive_Interactive_Wiring_Diagrams.html
Use my www.autodiagnosticsandpublishing.com/Stress_Loaded_Tester.html to test ECM grounds. So the ECM is connected to ground. Then the ECM has usually 3 or more sensor grounds outputs. These are provided by the ECMs internal circuitry. Same ground potential, but through the ECM.
@Rob and Kelli Bolettieri Yes, Pankaj Singh. Think of the 5 volt signal to the sensor as a base line, a reference point that the computer then can use to determine the input in volts , whether it is temp, throttle position, length & duration of injector pulse etc. If the computer doesn't see 5 volt reference then the calculations cannot be performed. Nothing to measure the programmed parameters & adjust them according to engine demand.
Thanks, your videos are so useful .. your videos on Electronic Throttle Body's tells me I have a problem, I have a bad Ecm ground at the starter relay, relay ground to battery positive terminal says 9 volts, even thou its 12.80 volts using the negative terminal as ground, no crank unless I connect a wire from the half inserted starter relay ground pin, to the chassis ground.
What if I do not see the MA draw on either the ecm ground or the 5 volt reference signal when wired up? I checked AC and DC to make sure but I do not get the referenced amount for testing; ~250ma or ~600ma.
@@ADPTraining could that be an indication of a bad ecm? I have a 2011 range rover that keeps giving me a P0087, but I have noticed that my MAP sensor Voltage in the scanner data keeps reading -29 Volts when connected and -27 volta when disconnected. At the return signal wire coming from the MAP sensor connected I see ~2.34 Volts. I also noticed my barometric Voltage is stuck at 3.54 Volts with no change when the MAP senosr is connected or disconnected. Also, my MAF sensor on bank 2 the date is reading .38 Volts but the signal wire reads .78 Volts. On the MAF sensor bank 1 I have a reading of .78 volts on the wire and the scanner. MAP sensor absolute pressure has a stuck reading of 98 kpa. No change with sensor connected or disconnected. In these vehicles with a low MAP sensor reading it will keep the fuel pressure at a default pressure witch leads me to believe I have a bad ecu, but this is the second ecu I put on it. I have checked for shorts, high impedance levels, shorts to voltage. This truck has been a nightmare for me. I just feel like I am over looking something..... I wired up everything the way your video instructed me and noticed I was not getting that mA current draw you stated. I thought it to be a bit strange. I did notice the resistor was getting hot, is that normal?
Hi my name is Hector and I'm having trouble with a 2010 Mercedes CL63 AMG 6.3l,I have misfires on cylinders 3,6,7 I checked the 12V feed and is good and I also checked with a noide light all 3 Faulty cylinders and the ground pulse seam to be very week,I also tried #1 cylinder with the light and that signal is much stronger, I'm looking to find out if you can please help me to get a wiring Diagram for the engine and also for the ABS module I don't have any voltage going in it thru the red and white wire Please Help Thank You.
Ok good, here you can order our interactive wiring diagram. You need two diagrams. We have to make these diagrams, since it's a software. Take a look. www.autodiagnosticsandpublishing.com/Automotive_Interactive_Wiring_Diagrams.html
Between sensor ground and 12 volt yes. But, you better STRESS test the ground as well. See my STRESS LOADED TESTLIGHT. autodiagnosticsandpublishing.com and here. www.autodiagnosticsandpublishing.com/Stress_Loaded_Tester.html
BROTHER ,i got a 2011 buick lacrosse 3.6l engine i been working on for a month plus ,its a no crank/start issue . it keeps blowing the # 10 20 amp fuse ,less than a year ago did same thing but i changed the starter relay and it fixxed the problem . it had no codes to read this time ,UO100 AND PO23F ON CODE READER BUT MY "BLUE DRIVER" AND APP , FOUND ABOUT 14 MORE CODES .any tips will be gladly appreciated ! thank You very much !
I don’t know if you will still respond but I have a 1999 Mazda Miata that had a o2 sensor short to ground and kept blowing the fuse. Stupidly I ran a hot wire in the fuse box on the engine fuse and now my 5v reference on pin 2h from the pcm to power the cps is only running at 1.9v. I was wondering if this is an easy fix
No it's not. Probably only an ECM REPLACEMENT fixes the issue. If you can't find it, we can also repair it for you. But, it's not cheap, sorry to be the Harbinger of bad need, but the issue has been created and takes a while to find. There are no schematic diagrams for ECMs. Go to my website if you want to get in touch with me, thank you, Mandy.
I have a 1995 jeep grand Cherokee 4.0 crank no start. I have no power to the coil. The auto shutdown relay has no ground im told the ECU is telling the car to not start... Can i get any advise? Id appreciate it
I rarely say this, but it sounds like the ECM is faulty. However, the ECM needs a cranky sensor input to activate the ASD relay. The Cherokee on those years was known for major No Start issues due to the crank sensor. Check that out first. Good luck.
@@ADPTraining crank sensor is good. There is power to the crank sensor and a ground. There is power to the cam sensor too but there is no power and no ground to the ignition coil. And i hear coil runs straight from the battery.
Just to confirm what you are saying, you connect the resistor (load), then you connect the volt meter to the same places so you are wired in parallel, not in series? For the ground test you do the same thing, yes? (You never say where the meter is connected in that test.) Also, sorry, but what do you mean by "connect" in this case? Are you back-probing the ECM connector to test the 5v ref wire?
I actually make a tool for that. www.autodiagnosticsandpublishing.com/Stress_Loaded_Tester.html So yes, say you want to test the ECM Sensor GROUND/Earth. Connect or probe between DLC Pin 4 and B+, and meter in parallel. Do this for about 5 seconds. Meter shouldn't go above 500 millivolts. This other tool does this automatically. www.autodiagnosticsandpublishing.com/OBD_2_DLC_Health_Checker.html
@@ADPTraining Thanks for your reply, parallel makes sense. And what about the 5v side? That was my main question about connecting, I presume you mean to backprobe? Or are you poking the wires? . itself