2G Another PTU

[Koda]

So I’ve went through 3 ptu’s and I’m still not sure why. After the first two I moved the location of it to under where the battery was. This time it gave me the random cylinder misfire code and started limping on two cylinders , I shut it off and turned it back on and it was fine , just cleaned the grounds up but haven’t drove it at all yet. PLEASE HELP. Ps: I’m not sure where the ground is located that comes out of the Ptu sensor itself and I want to make sure I didn’t miss that one.

 

[Buddy2]

So I’ve went through 3 ptu’s and I’m still not sure why. After the first two I moved the location of it to under where the battery was. This time it gave me the random cylinder misfire code and started limping on two cylinders , I shut it off and turned it back on and it was fine , just cleaned the grounds up but haven’t drove it at all yet. PLEASE HELP. Ps: I’m not sure where the ground is located that comes out of the Ptu sensor itself and I want to make sure I didn’t miss that one.

Make sure you are getting correct voltage on battery while your car is "idling". Do you know is number 1&4 out or 2&3? You need 14v @ battery while car is on (altenator). I think ptu grounds trough its mount so make sure grounds are good+ engine grounds and coils are working. I had exact same problems and i did replace every ignition part + cas but ultimately it was my altenator.

 

[Koda]

Make sure you are getting correct voltage on battery while your car is "idling". Do you know is number 1&4 out or 2&3? You need 14v @ battery while car is on (altenator). I think ptu grounds trough its mount so make sure grounds are good+ engine grounds and coils are working. I had exact same problems and i did replace every ignition part + cas but ultimately it was my altenator.

I’ll check the voltage now but I’m pretty confident it’s always over 14v but I have another coil pack I can try , and my spark plugs and coil wires are both brand new. The weird thing is the last 2 Ptu didn’t work after , they completely just stopped working all together. This one just stopped working right for a mile and then when I started the car again the tach was fine and all 4 cylinders were working again. So I thought it was a ground. And in another post I’ve seen people talking about a ground through the harness side that goes up beside where the battery is .

 

[DSMPT]

So I’ve went through 3 ptu’s and I’m still not sure why. After the first two I moved the location of it to under where the battery was. This time it gave me the random cylinder misfire code and started limping on two cylinders , I shut it off and turned it back on and it was fine , just cleaned the grounds up but haven’t drove it at all yet. PLEASE HELP. Ps: I’m not sure where the ground is located that comes out of the Ptu sensor itself and I want to make sure I didn’t miss that one.

The PTU ground is through pin #3 to the body ground on firewall, not body ground through its mount. IIRC, one of the bunch of 3~4 ground wires mounted by M6 bolt (10mm head) right next the battery (-) terminal. Anyways first, you should check the connector and pin's connections if they sit tight and trace all 7 wires from the PTU to check if they are all good, no sign of burnt, damage etc. If the voltage is not abnormal and all wiring/connections are good, I would try another good working ECU to see if this would happen again.

 

[Koda]

The PTU ground is through pin #3 to the body ground on firewall, not body ground through its mount. IIRC, one of the bunch of 3~4 ground wires mounted by M6 bolt (10mm head) right next the battery (-) terminal. Anyways first, you should check the connector and pin's connections if they sit tight and trace all 7 wires from the PTU to check if they are all good, no sign of burnt, damage etc. If the voltage is not abnormal and all wiring/connections are good, I would try another good working ECU to see if this would happen again.

I’ll check all 7 wires and make sure they are okay , battery voltage sits at 14.3 and my ECU is brand new just got it from ecmlink a month ago and it had this problem with the last ECU as well.

 

[spyderdrifter]

I’ll check the voltage now but I’m pretty confident it’s always over 14v.

Having too much voltage from the alternator can be just as bad as low voltage if not worse.

 

[Koda]

Having too much voltage from the alternator can be just as bad as low voltage if not worse.

Is 14.3v too much? Or is it normal

 

[mattp_65]

Is 14.3v too much? Or is it normal

Normal, with car running of course

 

[Koda]

Normal, with car running of course

Okay that’s what it’s been sitting at I hope it was a bad ground or something and hopefully I got it cleaned up because there was a couple questionable grounds that I found on the firewall

 

[yokotabrat]

Dumb question, but do you still have the PTU mounted to the stock bracket or some large metal piece? The transistors need a good heatsink to keep the part from exceeding temperature specs, especially with it being in a hot engine bay.

 

[Koda]

Dumb question, but do you still have the PTU mounted to the stock bracket or some large metal piece? The transistors need a good heatsink to keep the part from exceeding temperature specs, especially with it being in a hot engine bay.

It’s mounted on the block where the battery ground used to be . Underneath everything