2006 Kia Sportage, Crank but no start, no spark...ECM wont ground main relay

I will definitely take him up on it, I've got nothing to lose...

It was loaded with current

Thanks again Paul, I've had sometime to think about your tests and they do make sense as usual. I will do them as per your instructions and get back to you by the end of the week. Someone else mentioned that of course the circuit would work because I was jumping the switch side but the vehicle wouldn't start and run without me jumping the control side also at the same time. Again, I appreciate all the good advice and will follow it.

HI Paul, sorry for the late response. I did the two tests you told me to do. The one test I used incandescent bulb and connected one end to the battery and other end to Pin 67 at the ecm connector and the light didnt light up. The second test I grounded the circuit at the ecm pin 67 with T pin and jumper wire to ground and the main relay did click but vehicle wouldnt start. I think that this test says that the integrity of the circuit and fuse box is good however the driver for the ECM is cooked, right?

Didn't the vehicle run when you activated relay at fuse box earlier in your testing?

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Trod wrote: HI Paul, sorry for the late response. I did the two tests you told me to do. The one test I used incandescent bulb and connected one end to the battery and other end to Pin 67 at the ecm connector and the light didnt light up. The second test I grounded the circuit at the ecm pin 67 with T pin and jumper wire to ground and the main relay did click but vehicle wouldnt start. I think that this test says that the integrity of the circuit and fuse box is good however the driver for the ECM is cooked, right?

No sir. If the main relay activated when you grounded that circuit and the car still didn't start, then you are most likely missing a power feed or ground to the PCM .
If you only had a faulty driver for the main relay, the car would have started. You have another problem.

This is obviously an old post by now, but did you figure anything out?

BTW...
#1. That makes zero sense that "the vehicle wouldn't run unless it had both sides jumped". Aside from the fact it would cook the driver before it blew the 30A fuse... even if the ECM hypothetically was monitoring the control ground wire for a fault or any potential starting inhibit via the other drivers, it would want to see 0v during Key On, on the B/O wire. Jumping the control side would only take away the only load in the circuit- shooting 12v straight into the driver. Since the transistor is now an open circuit due to being cooked, there will always be 12v on that wire anyway, since the driver can't ground anything anymore. Now, this is all hypothetical, just to help you understand why that statement is not possible. If you still think that both had to be jumped to start it, you probably weren't jumping the terminals that you thought you were.

#2. Paul is telling you not to put an ECM in yet because, although you will now need one, he doesn't want you to potentially damage the new ECM. Need to figure out the original problem first.

#3. Paul didn't say to use a logic probe, he told you to use an incandescent test light (which draw little amperage) for a reason. using the test light puts a safe load on the circuit. Logic probes do not draw an amperage on the circuit, as they have their own power and ground. I honestly view logic probes as completely useless if you already own a DMM.

TheTechWhisperer wrote:
#2. Paul is telling you not to put an ECM in yet because, although you will now need one, he doesn't want you to potentially damage the new ECM. Need to figure out the original problem first.

#3. Paul didn't say to use a logic probe, he told you to use an incandescent test light (which draw little amperage) for a reason. using the test light puts a safe load on the circuit. Logic probes do not draw an amperage on the circuit, as they have their own power and ground. I honestly view logic probes as completely useless if you already own a DMM.

And I will add to your #2 statement and say, replacing the ECM will NOT get this car running based on the fact that grounding the main relay control didn't get it running either. You will need an ECM if you jumped the control side of the relay but this is only A problem, not THE problem. You added this one, maybe. I say maybe, because you may have gotten lucky if the ECM was missing a power feed and never had that circuit active when you jumped the relay. Not sure.

Also agree with #3 statement, logic probes are useless for troubleshooting in 95% of applications. It only takes a few volts to light an LED light in a logic probe and the amperage draw is in the micro-amp range. Get yourself a nice 200-300ma draw incandescent test light like the one I use.

First of all techwhisperer I didnt use a logic probe in the test that Paul told me to do, re-read my post, I used something that draws more amps....secondly paul is saying there is another input issue most likely a bad ground he never said anything about causing more damage...you appear to be one of those who likes to just antagonize...I now know why Paul probably doesnt post here anymore. I know the results of my tests, initially jumping the switch side had no effect to starting only after control saw voltage did it start and started multiple times. Ive since received Pauls book and obviously wont be rushing to get results anymore. If Im missing a power feed altogether how would that damage a said good known computer?

Thank you again Paul, I will start checking all my power feeds. I already checked many of the main grounds and they were fine. Im under a lot of pressure to get this vehicle up and running and a long list of other cars with dtcs and issues. Your book arrived last Saturday and I read the section on transistor drivers. Again I appreciate your approach to my dilemma while not all here have been so courteous in there words.

Trod,

I sincerely apologize if i came across antagonistic. Unfortunately, my verbal tone cannot be conveyed in text, but I assure you that I am the complete opposite of antagonistic. Paul can vouch for me, that my heart is only to help. As an instructor, my instinct was trying to break it down in different lingo to help you understand what Paul was saying, but I'm sorry that it came off as condescending instead and made you upset.

To answer your question: Jumping the switch side that was potentially missing the power feed would be one instance that no damage is done to ECM. However, we don't know... I think the power likely is not missing, since grounding the relay control made the relay click as you said. I just don't want to see you get burned by replacing the ECM and having the original pre-existing problem damage the new ECM... I have been there and made that expensive mistake, it really sucks.

Trod wrote: Thank you again Paul, I will start checking all my power feeds. I already checked many of the main grounds and they were fine. Im under a lot of pressure to get this vehicle up and running and a long list of other cars with dtcs and issues. Your book arrived last Saturday and I read the section on transistor drivers. Again I appreciate your approach to my dilemma while not all here have been so courteous in there words.

It is hard to gauge intent with text on a screen. Did you see TheTechWisperer's last comment to you? I think it was an awesome reply to you and I know he is reading this too and I want to give a personal thank you to him.
THIS is exactly why my community is so much better than others. It is in the heart of my people. I am honored to call you all friends.
With this community there is no bashing, respect of others and kindness are required. I got to see it first hand here.
Thank you guys.
And Trod, thank you for not getting too riled up, I could sense your frustration and you didn't let it get the best of you.

Very true. If you've ever spent any time in another forum you'll know that this one is much more friendly, helpful, and knowledgeable. Best one out there!

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