The Ever Popular P1300 CEL

[Shoke]

Hey man, I appreciate the updates. Keep at it.


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[ZionXIX]

Update:

Ok guys, I was able to remove the ECM and i almost stripped 1 of the damn screws. I could believe how stuck it was. Anyways, I took several photos of the board on both sides. I am going to try and post large photos so you guys can review them easier. I would like to embed them but I think i will post links to my dropbox photos so at least the links can stay here. I hate when 3rd party hosted photos vanish. It really negatively impacts people years down the road looking for the same information.

Back
https://www.dropbox.com/s/msbhon7qceu71l3/20160907_192612.jpg?dl=0
https://www.dropbox.com/s/47ydujyxuzaui7b/20160907_192714.jpg?dl=0

Front
https://www.dropbox.com/s/lq0w4jwezovt2so/20160907_192803.jpg?dl=0
https://www.dropbox.com/s/a3bxkeyudtpdeuc/20160907_192807.jpg?dl=0

Suspect area on front side
https://www.dropbox.com/s/bgmzih896nbkm0u/20160907_192912.jpg?dl=0
https://www.dropbox.com/s/9vodd8mnyyh611h/20160907_192937.jpg?dl=0

If Im not mistaken, that looks like the entrails of capacitor that leaked onto the board.
What do you more circuitry inclined people think?

Also I removed my MAF and tried to check the resistence but I dont know which pins to check. Here is a picture.

 

[bentos1]

Those are great pics of the ECM. That area you mentioned looks pretty crubulated. You could try cleaning the board with alcohol but something happened in that area You could look at a schematic to find out what that area does, but even then it would super complicated.

Here is the MAF troubleshooting:
http://tacoma.site40.net/4Runner_96-02_Repair&Wiring/techinfo.toyota.com/ileaf/02toyrm/02toypdf/02rmsour/2002/024runne/di/eg5vzfe/cip0100.pdf
http://tacoma.site40.net/4Runner_96-02_Repair&Wiring/techinfo.toyota.com/ileaf/02toyrm/02toypdf/02rmsour/2002/024runne/di/eg5vzfe/cip0101.pdf

Check your area for a 4runner for sale and offer $25 to borrow their ECU for 5 min. Maybe you could determine if that was part of the issue. Those crusty bits don't look so great. I wouldn't want to suggest replacing it unless it does turn out to be that part, they are expensive. Maybe a member here has a spare ECU that you could use for testing?

ECM pinout:
http://tacoma.site40.net/4Runner_96-02_Repair&Wiring/techinfo.toyota.com/ileaf/02toyrm/02toypdf/02rmsour/2002/024runne/di/eg5vzfe/terecm.pdf

Let us know the results of your MAF testing.

 

[TheDurk]

Update:

Ok guys, I was able to remove the ECM and i almost stripped 1 of the damn screws. I could believe how stuck it was. Anyways, I took several photos of the board on both sides. I am going to try and post large photos so you guys can review them easier. I would like to embed them but I think i will post links to my dropbox photos so at least the links can stay here. I hate when 3rd party hosted photos vanish. It really negatively impacts people years down the road looking for the same information.



If Im not mistaken, that looks like the entrails of capacitor that leaked onto the board.
What do you more circuitry inclined people think?

Also I removed my MAF and tried to check the resistence but I dont know which pins to check. Here is a picture.

I'd say you have it right on that cap.

As to the MAF, you can see the pin-outs for the '96 5VZ-FE MAF in the attached. However, I don't have the resistance specs for the early MAF type. Since they are interchangeable with the later one, I'll go out on a limb and link those.

http://tacoma.site40.net/4Runner_96-02_Repair&Wiring/techinfo.toyota.com/ileaf/02toyrm/02toypdf/02rmsour/2002/024runne/sf5vzfe/mafm/insp.pdf

The MAF is shown on the '96 EWD and the wire labels and pin numbers are given on the MAF box. Then to see the pin-out, go to the bottom and look at the diagram for plug M1.

 

[ZionXIX]

Those are great pics of the ECM. That area you mentioned looks pretty crubulated. You could try cleaning the board with alcohol but something happened in that area You could look at a schematic to find out what that area does, but even then it would super complicated.

Here is the MAF troubleshooting:
http://tacoma.site40.net/4Runner_96-02_Repair&Wiring/techinfo.toyota.com/ileaf/02toyrm/02toypdf/02rmsour/2002/024runne/di/eg5vzfe/cip0100.pdf
http://tacoma.site40.net/4Runner_96-02_Repair&Wiring/techinfo.toyota.com/ileaf/02toyrm/02toypdf/02rmsour/2002/024runne/di/eg5vzfe/cip0101.pdf

Check your area for a 4runner for sale and offer $25 to borrow their ECU for 5 min. Maybe you could determine if that was part of the issue. Those crusty bits don't look so great. I wouldn't want to suggest replacing it unless it does turn out to be that part, they are expensive. Maybe a member here has a spare ECU that you could use for testing?

ECM pinout:
http://tacoma.site40.net/4Runner_96-02_Repair&Wiring/techinfo.toyota.com/ileaf/02toyrm/02toypdf/02rmsour/2002/024runne/di/eg5vzfe/terecm.pdf

Let us know the results of your MAF testing.

I wouldnt even know where to start looking for that ECM schematic. Your diagram of the ECU is a newer version for like the 2002 model. It has 5 sections, my 96 only has 4 sections of the ECM. The ignition signals arent any where near that area but who really knows where those signals travel once inside the ECM.....

I did find an interesting thread about a guy who replaces capacitors on 90s model Lexus ECMs.
All my crazy Lexus issues SOLVED!! (ECU-leaking capacitor) - Club Lexus Forums

I have soldered a thing or 2 on PCB boards before. I would definitely be willing to try replacing the affected capacitors

 

[ZionXIX]

I'd say you have it right on that cap.

As to the MAF, you can see the pin-outs for the '96 5VZ-FE MAF in the attached. However, I don't have the resistance specs for the early MAF type. Since they are interchangeable with the later one, I'll go out on a limb and link those.

http://tacoma.site40.net/4Runner_96.../02rmsour/2002/024runne/sf5vzfe/mafm/insp.pdf

The MAF is shown on the '96 EWD and the wire labels and pin numbers are given on the MAF box. Then to see the pin-out, go to the bottom and look at the diagram for plug M1.

I did a resistance check on the left 2 pins and get basically infinite resistance. But the MAF has to be working since I'm not getting any codes for it right?

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[TheDurk]

I did a resistance check on the left 2 pins and get basically infinite resistance. But the MAF has to be working since I'm not getting any codes for it right?

Sent from my SM-G930T using Tapatalk

Wrong pins, dude. Resistance check is between THA and E2, which are on Pins 3 and 4. Looking at the meter, second from left and the middle one.

 

[ZionXIX]

Wrong pins, dude. Resistance check is between THA and E2, which are on Pins 3 and 4. Looking at the meter, second from left and the middle one.

Thanks, i could not find that anywhere. My manual is for the 2002 and it says to check the left 2 pins for resistance. I thought it might be the same on this older style since a lot of people say the old and new are interchangeable.

Pins 3 and 4 are showing 1,996 ohms. I think its suppose to be between 2200 and 2700 ohms @ 68oF according to the 2002 FSM. Its about 78oF at the time of testing.

 

[TheDurk]

Thanks, i could not find that anywhere. My manual is for the 2002 and it says to check the left 2 pins for resistance. I thought it might be the same on this older style since a lot of people say the old and new are interchangeable.

Pins 3 and 4 are showing 1,996 ohms. I think its suppose to be between 2200 and 2700 ohms @ 68oF according to the 2002 FSM. Its about 78oF at the time of testing.

Well, you could have found it in my previous post. That resistance may well be in spec as it goes down as temp goes up. You should also try the second test, as shown in the FSM link I posted above where you blow into the meter. On yours, you would use the second and fourth pins to do that.

They can be interchanged if you swap the airbox and repin the connector to reflect the different wiring.

http://bb.bc4x4.com/showthread.php?121852-1st-one-sold-so-this-ones-mine-Trekker-build&p=928386&viewfull=1#post928386

 

[ZionXIX]

Well, you could have found it in my previous post. That resistance may well be in spec as it goes down as temp goes up. You should also try the second test, as shown in the FSM link I posted above where you blow into the meter. On yours, you would use the second and fourth pins to do that.

Yea that is the same document that I have. It shows at the top to check ohms on the 1st 2 pins from the left. the 2nd step show a voltage check while in the "ON" position on the 3rd and 4th pins. Like I said, when I check resistance according to the 1st step I get "OL" on my meter.

So Im gonna say that there are 5 pins. Pin #1 in my mind is next to the airbox towards the front of the vehicle. Pin #5 is on the air tube side towards the back of the vehicle.

Pins 1 and 2 give me "OL" resistance
Pins 3 and 4 give me 1,996 ohms --> dspite the FSM saying nothing about checking those pins for resistence

Did this 5mins ago.......
Just for my "Challenge Accepted" mentality I checked the voltage of pins 3 and 4 while the iginition was "ON". Keep in mind the ECM is still unplugged. I am getting a steady 11.25 volts. I blew as hard as I could into the MAF and got no voltage change. I did have my leads switched around but I dont think that matters does it?

 

[ZionXIX]

Well, you could have found it in my previous post. That resistance may well be in spec as it goes down as temp goes up. You should also try the second test, as shown in the FSM link I posted above where you blow into the meter. On yours, you would use the second and fourth pins to do that.

They can be interchanged if you swap the airbox and repin the connector to reflect the different wiring.

1st one sold.. so, this ones mine .. Trekker build - Page 23

Ugh.....I read your post wrong. I tested the wrong pins. I might test it again shortly.


......A short time later.....

Checked voltage on pins 2 and 4. Got a steady 11.27volts that would occasionaly changed to 11.26. Blowing into the MAF made absolutely no difference. So is the MAF dead? or do I need the ECM connected to induce a voltage change?

 

[bentos1]

Ugh.....I read your post wrong. I tested the wrong pins. I might test it again shortly.


......A short time later.....

Checked voltage on pins 2 and 4. Got a steady 11.27volts that would occasionaly changed to 11.26. Blowing into the MAF made absolutely no difference. So is the MAF dead? or do I need the ECM connected to induce a voltage change?

Try the test with the ECM plugged in as well to see if anything changes. Is there another line plugged in to the MAF? I assume so, but in my ignorance I thought there was only the main connector where the DMM leads are plugged in to.

I think it would help if we could also narrow down the goobered area on the ECM to see if there is a blow capacitor. As you said it read infinite/open.

 

[ZionXIX]

Try the test with the ECM plugged in as well to see if anything changes. Is there another line plugged in to the MAF? I assume so, but in my ignorance I thought there was only the main connector where the DMM leads are plugged in to.

I think it would help if we could also narrow down the goobered area on the ECM to see if there is a blow capacitor. As you said it read infinite/open.

Update:

No need for pics here, just more of the same. So I reconnected the ECM and got very different voltage readings. When I cover the hole I get 0.585ish volts that hold steady. When directly blowing into the hole the voltage spikes as high as 3.1 volts. As long as its within normal range, I would say i have fully functioning MAF. Which is just one more thing I can cross off the check list. So you definitely need the ECM connected to observe the voltage changes.

 

[TheDurk]

Yea that is the same document that I have. It shows at the top to check ohms on the 1st 2 pins from the left. the 2nd step show a voltage check while in the "ON" position on the 3rd and 4th pins. Like I said, when I check resistance according to the 1st step I get "OL" on my meter.

So Im gonna say that there are 5 pins. Pin #1 in my mind is next to the airbox towards the front of the vehicle. Pin #5 is on the air tube side towards the back of the vehicle.

Pins 1 and 2 give me "OL" resistance
Pins 3 and 4 give me 1,996 ohms --> dspite the FSM saying nothing about checking those pins for resistence

Did this 5mins ago.......
Just for my "Challenge Accepted" mentality I checked the voltage of pins 3 and 4 while the iginition was "ON". Keep in mind the ECM is still unplugged. I am getting a steady 11.25 volts. I blew as hard as I could into the MAF and got no voltage change. I did have my leads switched around but I dont think that matters does it?

You really aren't paying attention. The FSM says exactly what WIRES to check when it says check the resistance between THA and E2. It then shows what pins those are on a 2002 MAF. However, you don't have a 2002 MAF, you have those wires on different pins, as the EWD I posted clearly shows. So you have to check THOSE pins to do the same thing on YOUR meter. (E2 and E2G are the same thing, it's the ground wire. )

I'd say you definitely should have the ECM connected to do the second test. switching the leads around makes no difference in these tests on a digital meter. You just might get a minus sign is all.

 

[ZionXIX]

You really aren't paying attention. The FSM says exactly what WIRES to check when it says check the resistance between THA and E2. It then shows what pins those are on a 2002 MAF. However, you don't have a 2002 MAF, you have those wires on different pins, as the EWD I posted clearly shows. So you have to check THOSE pins to do the same thing on YOUR meter. (E2 and E2G are the same thing, it's the ground wire. )

I'd say you definitely should have the ECM connected to do the second test. switching the leads around makes no difference in these tests on a digital meter. You just might get a minus sign is all.

[MENTION=10169]TheDurk[/MENTION] I apologise if my incompetence is frustrating. I really am trying to follow your instructions. I do appreciate your help. I took another look at the link you posted that has different diagrams of the connector pinouts for each year. I didnt even notice there were years written next to each diagram. Also I thought they were depicting the pin order for the MAF sensor itself, I now realize its the connector. I will mirror that order when I test the MAF again.



Of course now I look at it a 3rd time and it says "connector backside". So to make this easy, Is the wire closest to the airbox the E2G or +B?

 

[ZionXIX]

Update:

Hopefully this is the last post concerning the MAF. The Durk post a link to another forum that had a nice depiction of all three MAF pin out for the various model year 4runners. In the graphics they have written "connector backside". I found that description a little misleading as I originally thought it was showing the pin out as if you were looking at the backside of the plug staring at the wires. However when comparing their 2000 graphic to the FSM it appear that they are showing the inside of the connector that would normally be attached to the MAF. Knowing this its really more of a mirror reflection of the pins on the MAF itself.

1st one sold.. so, this ones mine .. Trekker build - Page 23

Here is my graphic where the pin out has been mirrored to show the order on the MAF itself. I got a 1,996 ohm reading for the (E2 - THA) pins, and a voltage range of (0.585 - 3.1v) when testing the (E2 - VG) pins. The FSM states that I should check the (E2G - VG) pins. But as TheDurk pointed out E2 and E2G are both grounds, so I dont see how there would be a difference in using either pin. Im satisfied that the MAF is operating at the correct resistance and voltage spec when air is passing through, unless someone wants to challenge me on it. And I learned that the ECM needs to be connected for the voltage to fluctuate in the MAF.

Now back to the problem at hand.......the P1300:frusty:

End of mini-rant.......

 

[bentos1]

Update:

Hopefully this is the last post concerning the MAF. The Durk post a link to another forum that had a nice depiction of all three MAF pin out for the various model year 4runners. In the graphics they have written "connector backside". I found that description a little misleading as I originally thought it was showing the pin out as if you were looking at the backside of the plug staring at the wires. However when comparing their 2000 graphic to the FSM it appear that they are showing the inside of the connector that would normally be attached to the MAF. Knowing this its really more of a mirror reflection of the pins on the MAF itself.

1st one sold.. so, this ones mine .. Trekker build - Page 23

Here is my graphic where the pin out has been mirrored to show the order on the MAF itself. I got a 1,996 ohm reading for the (E2 - THA) pins, and a voltage range of (0.585 - 3.1v) when testing the (E2 - VG) pins. The FSM states that I should check the (E2G - VG) pins. But as TheDurk pointed out E2 and E2G are both grounds, so I dont see how there would be a difference in using either pin. Im satisfied that the MAF is operating at the correct resistance and voltage spec when air is passing through, unless someone wants to challenge me on it. And I learned that the ECM needs to be connected for the voltage to fluctuate in the MAF.

Now back to the problem at hand.......the P1300:frusty:

End of mini-rant.......

Were you going to replace the capacitor on the ECM board? Maybe that will be the last resort deal. I dont suggest buying one until you verify the issue the best you can, but they arent too pricey on flea-bay: Toyota Tacoma ECU: Car & Truck Parts | eBay

 

[ZionXIX]

Were you going to replace the capacitor on the ECM board? Maybe that will be the last resort deal. I dont suggest buying one until you verify the issue the best you can, but they arent too pricey on flea-bay: Toyota Tacoma ECU: Car & Truck Parts | eBay

I am really tempted to try and replace those capacitors and buy extras for the remaining. I have been researching this. The capacitors are extremely cheap, even for the high quality 5000hr ones. That link I posted about replacing capacitors on a Lexus ECU is extremely detailed on what kind of caps and where to get them. I already have an iron, solder, and Flux. I would like to get a solder pump and some Flux wire. I found a kit on amazon for less than $10. If it doesn't work, I am about ready to replace the ECU anyway.

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[TheDurk]

I am really tempted to try and replace those capacitors and buy extras for the remaining. I have been researching this. The capacitors are extremely cheap, even for the high quality 5000hr ones. That link I posted about replacing capacitors on a Lexus ECU is extremely detailed on what kind of caps and where to get them. I already have an iron, solder, and Flux. I would like to get a solder pump and some Flux wire. I found a kit on amazon for less than $10. If it doesn't work, I am about ready to replace the ECU anyway.

Sent from my SM-G930T using Tapatalk

There is a known fix for the brain for the A/C on e36 BMWs (90s 3-series) that involves replacing a similar cap--it's actually in a nastier spot. Perfectly doable if you have some decent soldering technique. I did it fairly easily, but I built HeathKits as a kid. (dating myself). Caps are caps, get the mfd and polarity right and you're golden. You don't need flux, just good rosin core electronic solder (yes, with lead). A light 25w iron is best for PCB work. Go easy, it's easy to damage the board.

https://www.amazon.com/Alpha-Metals-am31605-4oz-032elec-Solder/dp/B000G36BYU/ref=sr_1_2?s=hi&ie=UTF8&qid=1473458287&sr=1-2&keywords=31605

Remember to verify how the polarity is on the old cap before you remove it. You don't want to try to figure it out later.

 

[ZionXIX]

There is a known fix for the brain for the A/C on e36 BMWs (90s 3-series) that involves replacing a similar cap--it's actually in a nastier spot. Perfectly doable if you have some decent soldering technique. I did it fairly easily, but I built HeathKits as a kid. (dating myself). Caps are caps, get the mfd and polarity right and you're golden. You don't need flux, just good rosin core electronic solder (yes, with lead). A light 25w iron is best for PCB work. Go easy, it's easy to damage the board.

What are the consequences of using a basic lead free silver solder?

Edit: can I use a really high quality caps, like the ones that looks like they are cover in a metal sheath?

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