Ls2 swap dbw throttle troubleshooting
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Ls2 swap dbw throttle troubleshooting I am using the electronic throttle body in my LS2 swap (into an e36 bmw m3). Got the J1 connector with OBD2 and Throttle body pigtail from EFI connection. Engine came with wiring harness which included other two connectors to ecm, as well as the electronic pedal assembly from the se car (2005 pontiac gto). Plugged it all in, but throttle body does not move with pedal when testing it.
I've checked to make sure the wiring to the pedal is correct to the pedal since I know it is different between gto and Vette. Checking with hp tuners, the car is throwing a p2101 code, which has something to do with the TAC. Any ideas on what I should be checking? Thanks in advance!
I've checked to make sure the wiring to the pedal is correct to the pedal since I know it is different between gto and Vette. Checking with hp tuners, the car is throwing a p2101 code, which has something to do with the TAC. Any ideas on what I should be checking? Thanks in advance!
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Thanks for the help and bump!
Given that the wiring harness is the original one that came with the motor, and I have not messed with it, but he c1 pigtail is aftermarket to the throttle pedal, would it make more sense to switch those on the pedal? If that doesn't work, I'll try the 12v source to the throttle body. Thanks again!
Given that the wiring harness is the original one that came with the motor, and I have not messed with it, but he c1 pigtail is aftermarket to the throttle pedal, would it make more sense to switch those on the pedal? If that doesn't work, I'll try the 12v source to the throttle body. Thanks again!
Thanks for the help and bump!
Given that the wiring harness is the original one that came with the motor, and I have not messed with it, but he c1 pigtail is aftermarket to the throttle pedal, would it make more sense to switch those on the pedal? If that doesn't work, I'll try the 12v source to the throttle body. Thanks again!
Given that the wiring harness is the original one that came with the motor, and I have not messed with it, but he c1 pigtail is aftermarket to the throttle pedal, would it make more sense to switch those on the pedal? If that doesn't work, I'll try the 12v source to the throttle body. Thanks again!
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Thread Starter
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Sorry for the delay everyone, been too busy with kids to spend much time in the shop!
Wish I had an answer, but I haven't got it working yet. I did double check the wiring of the pigtail and it is correct. It was a complete C1 connector with dbw pigtail and obd2 pigtail for a GTO LS2 from EFI Connectors. They did not mess up!
Apparently, the electronic throttle body is supposed to open and close quickly as a check when you first turn on the ignition and it does not do that either. I am guessing that I have either missed some grounds or powered wires to the ecu somewhere, either from the c101 or c206 connectors, or the throttle boy is actually faulty.
Someone mentioned to try and supply a 5v supply directly to the throttle body to see if it would respond, but I haven't quite figured out how to do that...
I will have more time on Friday to troubleshoot, so if anyone has any suggestions, I am all ears!
Wish I had an answer, but I haven't got it working yet. I did double check the wiring of the pigtail and it is correct. It was a complete C1 connector with dbw pigtail and obd2 pigtail for a GTO LS2 from EFI Connectors. They did not mess up!
Apparently, the electronic throttle body is supposed to open and close quickly as a check when you first turn on the ignition and it does not do that either. I am guessing that I have either missed some grounds or powered wires to the ecu somewhere, either from the c101 or c206 connectors, or the throttle boy is actually faulty.
Someone mentioned to try and supply a 5v supply directly to the throttle body to see if it would respond, but I haven't quite figured out how to do that...
I will have more time on Friday to troubleshoot, so if anyone has any suggestions, I am all ears!
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DBW problems Can only tell you how I solved MY problem. My LM4 came out of an '03 Trailblazer and I got the TAC and pedal too. It would not work above about 30 % and finally figured out that the tune was '05 and would not work with my '03 TAC and pedal. Finally used TAC 12588923 and pedal 15821777. To recap, when I had the ECU reprogrammed to eliminate EGR, VATS etc. it also also voided the '03 TAC and pedal because a common practice is to use an updated '05 tune. Not sure if that's anywhere near your problem but maybe a place to look.
Can only tell you how I solved MY problem. My LM4 came out of an '03 Trailblazer and I got the TAC and pedal too. It would not work above about 30 % and finally figured out that the tune was '05 and would not work with my '03 TAC and pedal. Finally used TAC 12588923 and pedal 15821777. To recap, when I had the ECU reprogrammed to eliminate EGR, VATS etc. it also also voided the '03 TAC and pedal because a common practice is to use an updated '05 tune. Not sure if that's anywhere near your problem but maybe a place to look.
Tipsy
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From: New Taxes York
Hmmm... I'm trying to remember exactly what I did to mine to try and help you.
I have the exact same setup, and that same C1\OBDII harness from EFI Connections.
As for testing the TB with 5VDC, you'll need a +5 volt DC source of some type. Supply the power pin (on the TB itself) with the +5v, and ground the TB GND pin to the chassis or engine block (if the engine is grounded to the car). The blade should actuate.
I didn't have to supply stand-alone power to the pedal, but the OBDII did have to have it's own +12vdc power supplied to it. I'm going to assume there is power supplied to the ECM that in turn enables the acc. pedal. I didn't add any grounds anywhere, except from battery to body, engine to body, and engine to chassis.
I'll break out my folder when I get home and list what I powered and how. PM me tomorrow or when you get a chance to troubleshoot and remind me.
I have the exact same setup, and that same C1\OBDII harness from EFI Connections.
As for testing the TB with 5VDC, you'll need a +5 volt DC source of some type. Supply the power pin (on the TB itself) with the +5v, and ground the TB GND pin to the chassis or engine block (if the engine is grounded to the car). The blade should actuate.
I didn't have to supply stand-alone power to the pedal, but the OBDII did have to have it's own +12vdc power supplied to it. I'm going to assume there is power supplied to the ECM that in turn enables the acc. pedal. I didn't add any grounds anywhere, except from battery to body, engine to body, and engine to chassis.
I'll break out my folder when I get home and list what I powered and how. PM me tomorrow or when you get a chance to troubleshoot and remind me.
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So I'm trying to work through this today.
The Throttle body works if supplied with a 5v source, so that's not it.
The TAC connector, with the ignition on has a 5v source when checking coins A and E (5V reference), so there is power to that plug.
When checking pins A and B (throttle motor voltage), there is 0V when turning the ignition on (shouldn't there be a test to open and close the throttle quickly on startup?), and nothing changes when pressing on the pedal.
I do not believe there to be an issue with either the throttle body itself or the wiring to the throttle body. Something else must be mucked up, just not sure where?
Thanks for all the help!
The Throttle body works if supplied with a 5v source, so that's not it.
The TAC connector, with the ignition on has a 5v source when checking coins A and E (5V reference), so there is power to that plug.
When checking pins A and B (throttle motor voltage), there is 0V when turning the ignition on (shouldn't there be a test to open and close the throttle quickly on startup?), and nothing changes when pressing on the pedal.
I do not believe there to be an issue with either the throttle body itself or the wiring to the throttle body. Something else must be mucked up, just not sure where?
Thanks for all the help!
On The Tree
Joined: Sep 2012
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From: New Taxes York
Re-seat the connector on the pedal assembly and try again.
If you have a multimeter, set it to check continuity. Disconnect the harness from the pedal and then try to probe the appropriate pins on the pedal connector and actuate the pedal. The Ohms reading should change as the pedal in moved.
If that's good, then it's definitely not talking to the ECM for some reason.
If you have a multimeter, set it to check continuity. Disconnect the harness from the pedal and then try to probe the appropriate pins on the pedal connector and actuate the pedal. The Ohms reading should change as the pedal in moved.
If that's good, then it's definitely not talking to the ECM for some reason.
On The Tree
Joined: Sep 2012
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From: New Taxes York
It'll be easier for me to tell you which wires of the C1 harness I DIDN'T use than to tell you the wires I did. I can put together a list when I get home...I didn't drive it to work today.
Both of those 5V references need to be there from the ECM to the pedal.
Can you scan the OBDII and get any trouble codes?
Read this:
http://hsv-gts.ls2.com/TAC%20System.pdf
http://hsv-gts.ls2.com/TP,TAC,APP.pdf
Both of those 5V references need to be there from the ECM to the pedal.
Can you scan the OBDII and get any trouble codes?
Read this:
http://hsv-gts.ls2.com/TAC%20System.pdf
http://hsv-gts.ls2.com/TP,TAC,APP.pdf
Last edited by HwyStarJoe; May 22, 2015 at 12:49 PM.
Thread Starter
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There was no need to splice, since the C1 connector that I bought comes wired with connectors for throttle pedal and obd2 port attached.
I will trace the wiring for the position 6 5V reference to make sure all is well with it, but everything came prewired correctly from EFI connection.
I will trace the wiring for the position 6 5V reference to make sure all is well with it, but everything came prewired correctly from EFI connection.
On The Tree
Joined: Sep 2014
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From: St. Paul, MN
Sorry, my confusion on what you bought. Thought it was like a pigtail setup. Could also check that all the connectors are seating, and that a pin didn't push out a little bit. I've read about lots of loose pins causing throttle issues.
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Sorry for how long it has taken for me to update this thread, but its been a busy summer waterskiing and wake surfing!
I had the time to get back in the shop and tackle this throttle that is still not working. I've checked all of the wiring and it checks out fine. I've back probed all of the pinouts on the throttle and they function fine. The problem, I believe, lies in the ecu. I do have HP tuners, its what I used to disable VATS in order to get the motor running. The only thing I think could be happening is that I am in limp mode. Does anyone know how to check that and disable it with HP tuners? Any other thoughts? Thanks in advance!
I had the time to get back in the shop and tackle this throttle that is still not working. I've checked all of the wiring and it checks out fine. I've back probed all of the pinouts on the throttle and they function fine. The problem, I believe, lies in the ecu. I do have HP tuners, its what I used to disable VATS in order to get the motor running. The only thing I think could be happening is that I am in limp mode. Does anyone know how to check that and disable it with HP tuners? Any other thoughts? Thanks in advance!
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Well, it took slightly under a year but I finally figured it out! Apparently pin 14 on the c1 connector is the one that receives ignition power to run the throttle body. I had hooked it up to an accesory ignition power supply on my fuse box, and guess what? Since it was an extra wire, it had no fuse. Put in a fuse and guess what? Works like a charm. Amazing how hours of troubleshooting and tracing wires could have been fixed so kuch easier and sooner! Oh well, now on to cooling, as long as life doesn't get in the way again!!
Thanks to everyone who helped. Cheers!
Thanks to everyone who helped. Cheers!