I'd start your diagnosis by checking out the 444 & 447 codes. Those codes suggest the power supply to the evap system control solenoids has gone open circuit which might be as simple as a blown fuse. The purge control solenoid is at the back of the engine behind the inlet manifold and should be fairly easy to access. It has a 2 hoses coming off it and has a two terminal connector. One of the two terminals should be a 12V supply. You can test with a 12V test lamp or a voltmeter. With the ignition on, disconnect the solenoid connector and check for power on each of the terminals. If you find there is no 12V supply then check your fuses. If your lucky all the other codes will be symptoms of that power supply issue. If you find there is a good 12V then I'd go back to the PCM and make sure you've correctly fitted all the connectors. It would also be worth checking that none of the pins on the PCM sockets have bent and are misaligned with the plug.

Let us know how you get on.

Scottie.

 

When you say " Installed them and still no change in code status."

Are you clearing the codes with your scan tool? I'm not an expert on this, but I'm pretty sure once those codes are set it will take a bunch of complete cold-->warm engine cycles before they will reset on their own.

 

Scottie!thanks for the reply.
I am getting close to 12v at the 1st pin on the evap control solenoid, 12 v on one pin of the right upstream o2 sensor and 10v on the engine Coolant temp sensor. Checked all the fuses, none blown. All pins are aligned on the ecu and seem to be fitting good with the cables.

It seems strange to me. Also the car will not start not sure if I mentioned the no spark issue.

 

Hyca, yes they were cleared with a scan tool but came right back. The computer is reading the coolant temp at an incorrect temp as well as the 92 sensors not havong ilany chnage in vlotsge upop acceleration. I know at least that something is not jiving and it's not just a matter of clearing the codes. Thanks though.

 

Sorry, I somehow missed your reply to my last post. I just saw your other thread and got a sense of deja vu than made me come back here.

Interesting that you have 10V on one of the coolant temp sensor wires. What voltage was the voltage on the other? 5ish Volts? Interesting too that the engine doesn't start...is that still the case?

 

This is what happens when someone has two threads running relating to the same subject. It gets messy. I'll stick with this thread.

Quote from "Where does the ground converge from the ecu on a 2000 hyundai sonata GLS V6 2.5L?"

Rechecked the voltage
Battery 11.4
Nothing at the Coolant temp sensor
11.4 at tps
11.4 at evap
I thought I had voltage at coolant sensor but on recheck nothing.
I'm should it be 5v coming to the sensors?
I was thinking ground when I thought all had power to them.

It could be a ground fault. You shouldn't have 11.4V on the TPS. It works on a 5V supply, but if the sensor ground is open circuit you could have 11.4V on the ground wire.
What wire/terminal on the TPS connector has 11.4 volts?

 

Your right. I just hot antsy when I didn't hear back. I don't see an option to delete one. I am using the mobile version. Not sure if that matters. Anyway.
Thank you for your willingness to help either way.
Looking down at the female connection and front probing bottom right reeds 11.4 and all others read about 0.2 v. (Reading 0.2 on the 200mv setting, not 100% I'm reading that right)

 

Is this a 3 terminal TPS? On a V6 engine the center terminal is normally the sensor ground. So connect you red meter lead to battery positive and the black to the center terminal and you should get 12ish volts.

 

I must have the wrong connector. I have 4 pins. Connector right by coolant temp sensor feeding from the same cable.

 

Ok now that I have the right sensor.
There is ground present at 11.8 in center pin with key off and 11.2 with key on using the red probe at the pos batt cable and black touching the metal recessed in the connector.

Putting black probe on negative bat terminal and red on metal of other 2 pins meter read no voltage.

Battery reads 11.8
Ecu fuse reads 11.2

 

Just to make sure your looking at the correct sensor...photo showing the TPS below.
With the sensor disconnected, the two outer terminals should be approx 5V with the ignition switched on.

 

Yep that's the one. Both outer are reading nothing.

 

You think that could be bad ecu?

It's still not starting, no spark.
And no reference voltage to sensors from ecu/pcm.
Doesn't sound good.
I was hoeping for a fuse.

 

Unplug the sensors on that rail and see if you still have zero. It might be a short in a sensor of in a wire that keeps it "low".
See here the schematic of my 2000.

 

Thanks for the diagram SoNic. I don't have much on the 2.5 V6. I don't think they sold anything with that engine here in the UK.

It doesn't look like there are any other sensors directly connected to that 5V supply though although the fuel tank pressure sensor might be off the same supply but linked internally within the PCM. Still, it could be a short on the wiring pulling the 5V low. Probably the best way to confirm would be to isolate the 5V where it exits the PCM. If the 5V is present at the PCM connector then the PCM is OK. If there still isn't any 5V with the rest of the circuit isolated then I'd check all the PCM power supplies & grounds. If there isn't any fault there then it looks like the 5V regulator inside the PCM has failed.

Fixed a car with this same fault recently using a USB phone charger :laugh:

 

That's cool.
I did assume that the output is protected... I guess you still can fry it.

 

I'm sure it will be protected from short circuits but it can fail in other ways. In the car I fixed with the phone charger there was a high resistance within the PCM. There was only about 3 Volts at the output when the wire was isolated from the sensors. As soon as a load was applied even that got pulled practically to ground. It was an older car and the cost of a replacement PCM plus having the car recovered to the dealer to have the immobilizer, etc recoded, it wasn't going to be a cost effective repair. So, with nothing to loose I tried the phone charger trick and that got it running again...for a while at least

Scottie.

 

That USB power supply is pretty ingenious!

OK,
How do I know what pin out of the ECU should be sending voltage?
For example in the diagram provided (Thank you SoNic67) the Engine Coolant Temp Sensor has a green wire going in ECU at 24. Does that mean pin 24? Then there is only 1 other wire listed coming from the sensor (black/white) and it goes to ground. So where is the reference voltage, because I know know it's a 3 pin connector!!?
Sorry if these are dumb questions. Just trying to sort everything out.

 

My buddy has a nicer scan tool. He let me borrow it, and it is reading a couple other codes specific to the model and descriptions for each code.
Not sure if this will help but figured it couldn't hurt

U0D00 See Service manual
P0123 Throttle Position Sensor A Circuit High Input
P0444 Evaporative Emission System Purge Control Valve Circuit Open
P0447 Evaporative Emission System Vent Control Circuit circuit Open
P0453 Evaporative Sensor / Switch High Input
P0118 Engine Coolant Temperature Sensor Circuit High Voltage
*P1505 Kick Down Servo Switch
* P1507 Manifold Absolute Pressure - Abnormal

*= New Codes

The charcoal canister in the driver side rear seems to be toast. I pulled it today and activated charcoal was falling out of it. There was a decent amount lodged in the large hose leaving the evap canister going to the fuel tank. I emptied it out and put a metal type mesh in between to keep any more charcoal from coming out until I can figure out the electrical issue.

 

My buddy has a nicer scan tool. He let me borrow it, and it is reading a couple other codes...
*P1505 Kick Down Servo Switch
* P1507 Manifold Absolute Pressure - Abnormal

His tool might look nicer but it's showing codes that aren't valid for your engine. AFAIK, the 2.5 doesn't have a MAP sensor, it has a MAF. That's what's shown on SoNic's schematic anyway.

Engine Coolant Temp Sensor has a green wire going in ECU at 24. Does that mean pin 24?

Yes, but the PCM has more than one connector. If you look down the list of pin numbers on the diagram from 24 you will see "C94-3" at the bottom. That is the designation of the connector that those terminals are fitted to. There should be a page in the diagram that shows the actual connector terminal locations for each of the PCM connectors to help identify the correct wires. There is a good chance that there will be several wires that are the same colours but for totally different circuits.

 

That is a huge help. thank you. The diagram makes more sense now.
Am I correct in assuming the bottom of the ECU on the diagram is the left side when mounted on the car then?

If I am reading this right by checking pin 10 on connector c94-3, I should be getting 5v from the ECU on this grn/wht line.
Thats a place to start!!
Since my PCM is in the center console, putting the black lead on the battery will not be a option. Should I just use a ground pin on the ECU or will that affect my results?
When determining the pin number on a specific connector does one start at the top left and count left to right then top to bottom with the next row?

Yes the car has a mass air flow and not a MAP so I was confused about that myself. Also confussed by the reporting of an open circuit and a high input. I thought if the circuit was open no signal could come through.

 

For reading the codes I am using an ELM327 bluetooth clone from eBay and my Android phone (with Torque app). Don't get the "new" ver 2.1 clones, they are bad, get a ver 1.5, it works. On US cars, Hyundai OBDII protocol is different from Ford or GM vehicles.
Pinout numbers I think that they are marked on the connector.

 

Thanks SoNic67, I'll check the beast out on fri and you guys know what I found. I work 2 24's in a row or would be doing it sooner.

 

I forgot to add, my ground was bad at the connection under the battery tray (bolt on the fender), I replaced the whole wire.
Also I had replaced three MAF sensors (two in warranty, one non-OE on my dime, that last one seemed to work better).
Look also for TSB's affecting your vehicle: https://www.automd.com/recall-tsb/search/?year=101&make=32&model=911


It might not be your case.

 

No power coming from the ecu.
Has power going to it but nothing coming out.
Called the stealership for advice and they said the computer is probably blown due to the fact I didn't torque the computer back down to spec when I reinstalled it.
Does that sound plausible?
I was thinking the computer, but what would torque have to do with it?

 

Before you buy an ECU, try the external +5V supply trick, maybe it will work...
You can find something like this on eBay, or you can make one yourself with an integrated stabilizer from the family 7805. The radiator tab is connected to the ground.

As for installing the ECM - high torque might bend and break traces/connectors inside. It would have to be serious torque differences though.

 

Before you buy an ECU, try the external +5V supply trick

Yeah, defo worth a try but you need to make sure it wasn't a sensor/wiring short that damaged the PCM's internal regulator in the first place or you'll very quickly find yourself right back to square one again.