LS 5.3 engine dies while driving DBW Throttle
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also, reading the trouble code description on the scanner (which could be wrong)
"TP1 sensor signal shorted to TP2 sensor signal"
the scanner is telling you that pin G is shorted to pin F somewhere (take this with a grain of salt, but also take it at face value for starters). Think about it - where is the voltage on pin G coming from? Since pin G has a pull down to ground, it should always be at 0V when nothing is plugged in to the tac module. if it's not, then its shorted to a something that is putting voltage on it, whether in the wiring or internal to the TAC module. And that's what the P2135 is telling you.
with the key off , measure the resistance between pins G and F. it should be very high. try wiggling the 8 pin connector around as well while you're measuring and see if anything changes. If you ever see a reading of less than 500 ohms or so, then there's your issue. If you never see a short there, also check pin G to pin H, and pin G to pin E. "Hey bob, why are you suggesting those pins in particular" great question, pins H and E are the 5V sources for the sensors. For pin G to have 5V on it is needs to be shorted to SOMETHING that is supplying voltage. Pin F is the most likely culprit based on the P2135, but the other two are possibilities as well.
my bet is that the issue is somewhere in the 8 pin connector going to the throttle body. I have seen issues there before where the crimps were either poorly done from the factory or just failed over time. I'm sure you can find a youtube video regarding how to remove the wires from that connector and inspect them.
"TP1 sensor signal shorted to TP2 sensor signal"
the scanner is telling you that pin G is shorted to pin F somewhere (take this with a grain of salt, but also take it at face value for starters). Think about it - where is the voltage on pin G coming from? Since pin G has a pull down to ground, it should always be at 0V when nothing is plugged in to the tac module. if it's not, then its shorted to a something that is putting voltage on it, whether in the wiring or internal to the TAC module. And that's what the P2135 is telling you.
with the key off , measure the resistance between pins G and F. it should be very high. try wiggling the 8 pin connector around as well while you're measuring and see if anything changes. If you ever see a reading of less than 500 ohms or so, then there's your issue. If you never see a short there, also check pin G to pin H, and pin G to pin E. "Hey bob, why are you suggesting those pins in particular" great question, pins H and E are the 5V sources for the sensors. For pin G to have 5V on it is needs to be shorted to SOMETHING that is supplying voltage. Pin F is the most likely culprit based on the P2135, but the other two are possibilities as well.
my bet is that the issue is somewhere in the 8 pin connector going to the throttle body. I have seen issues there before where the crimps were either poorly done from the factory or just failed over time. I'm sure you can find a youtube video regarding how to remove the wires from that connector and inspect them.
Last edited by bobcratch; Jan 30, 2025 at 07:57 AM.
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also, reading the trouble code description on the scanner (which could be wrong)
"TP1 sensor signal shorted to TP2 sensor signal"
the scanner is telling you that pin G is shorted to pin F somewhere (take this with a grain of salt, but also take it at face value for starters). Think about it - where is the voltage on pin G coming from? Since pin G has a pull down to ground, it should always be at 0V when nothing is plugged in to the tac module. if it's not, then its shorted to a something that is putting voltage on it, whether in the wiring or internal to the TAC module. And that's what the P2135 is telling you.
with the key off , measure the resistance between pins G and F. it should be very high. try wiggling the 8 pin connector around as well while you're measuring and see if anything changes. If you ever see a reading of less than 500 ohms or so, then there's your issue. If you never see a short there, also check pin G to pin H, and pin G to pin E. "Hey bob, why are you suggesting those pins in particular" great question, pins H and E are the 5V sources for the sensors. For pin G to have 5V on it is needs to be shorted to SOMETHING that is supplying voltage. Pin F is the most likely culprit based on the P2135, but the other two are possibilities as well.
my bet is that the issue is somewhere in the 8 pin connector going to the throttle body. I have seen issues there before where the crimps were either poorly done from the factory or just failed over time. I'm sure you can find a youtube video regarding how to remove the wires from that connector and inspect them.
"TP1 sensor signal shorted to TP2 sensor signal"
the scanner is telling you that pin G is shorted to pin F somewhere (take this with a grain of salt, but also take it at face value for starters). Think about it - where is the voltage on pin G coming from? Since pin G has a pull down to ground, it should always be at 0V when nothing is plugged in to the tac module. if it's not, then its shorted to a something that is putting voltage on it, whether in the wiring or internal to the TAC module. And that's what the P2135 is telling you.
with the key off , measure the resistance between pins G and F. it should be very high. try wiggling the 8 pin connector around as well while you're measuring and see if anything changes. If you ever see a reading of less than 500 ohms or so, then there's your issue. If you never see a short there, also check pin G to pin H, and pin G to pin E. "Hey bob, why are you suggesting those pins in particular" great question, pins H and E are the 5V sources for the sensors. For pin G to have 5V on it is needs to be shorted to SOMETHING that is supplying voltage. Pin F is the most likely culprit based on the P2135, but the other two are possibilities as well.
my bet is that the issue is somewhere in the 8 pin connector going to the throttle body. I have seen issues there before where the crimps were either poorly done from the factory or just failed over time. I'm sure you can find a youtube video regarding how to remove the wires from that connector and inspect them.
Thread Starter
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I will check for resistance between G&F, G&H, G&E with Key Off and report back. Will also check the 8 pin TPS connector, the pigtail used in the harness looks difference than the factory, the pins are kinda square and can see them at the top, the factory connect has the pins buried inside the plastic cover. I can even cut off the pigtail and try one of the factory connectors I have.
- G & F = 0.440 MΩ
- G & H = 0.316 MΩ
- G & E = 0.315 MΩ
Last edited by Tma120; Jan 30, 2025 at 04:05 PM.
Here's a simple way to isolate just the wiring.
Disconnect at the Throttle Body and the Connector at the Tac Module.
Use the meter do a continuity check between all this:
1 & G
11 & F
1 & F
11 & G
See what you get there.
Disconnect at the Throttle Body and the Connector at the Tac Module.
Use the meter do a continuity check between all this:
1 & G
11 & F
1 & F
11 & G
See what you get there.
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Nothing between 1&F and 11&F
Last edited by Tma120; Jan 30, 2025 at 03:54 PM.
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On The Tree
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Thread Starter
On The Tree
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I haven’t seen that issue since I replaced the Throttle body over a week ago now.
Well, there's that.
I don't think any of us asked if the code was still there when you changed that TPS out, or the whole Throttle Body, however you did it. We were tracking on checking wiring given you had voltage in places you shouldn't have.
Maybe in the TPS itself the two individual circuits contacted somehow.
You still have 5v or close to it on G, D, or B?
As mentioned F will have 5v given it's a pull-up circuit.
I don't think any of us asked if the code was still there when you changed that TPS out, or the whole Throttle Body, however you did it. We were tracking on checking wiring given you had voltage in places you shouldn't have.
Maybe in the TPS itself the two individual circuits contacted somehow.
You still have 5v or close to it on G, D, or B?
As mentioned F will have 5v given it's a pull-up circuit.
Thread Starter
On The Tree
Joined: May 2024
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Well, there's that.
I don't think any of us asked if the code was still there when you changed that TPS out, or the whole Throttle Body, however you did it. We were tracking on checking wiring given you had voltage in places you shouldn't have.
Maybe in the TPS itself the two individual circuits contacted somehow.
You still have 5v or close to it on G, D, or B?
As mentioned F will have 5v given it's a pull-up circuit.
I don't think any of us asked if the code was still there when you changed that TPS out, or the whole Throttle Body, however you did it. We were tracking on checking wiring given you had voltage in places you shouldn't have.
Maybe in the TPS itself the two individual circuits contacted somehow.
You still have 5v or close to it on G, D, or B?
As mentioned F will have 5v given it's a pull-up circuit.
Yes I still have 4.93v on both G/F.
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Now with the TPS connect unplugged, maybe it reading it as being fully opened? Maybe we’re barking at the wrong tree, I dont know, that why i asked if someone can get some readings on theirs and let us know.
Last edited by Tma120; Jan 31, 2025 at 10:52 AM.
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Read this below from our friend AI:
When the pigtail is unplugged from a DBW throttle body, Pin G (which is typically the Throttle Position Sensor (TPS) ground or signal return) could indeed show 5V (or near 5V), and here's why:
When the pigtail is unplugged, you may observe a floating voltage due to the circuit being incomplete. This is especially true if the TPS signal wire or other pins in the throttle body are still connected to the ECU or the throttle actuator control (TAC) module, which may cause the voltage to be pulled to 5V due to the way the system is designed.
In other words:
When the pigtail is unplugged from a DBW throttle body, Pin G (which is typically the Throttle Position Sensor (TPS) ground or signal return) could indeed show 5V (or near 5V), and here's why:
When the pigtail is unplugged, you may observe a floating voltage due to the circuit being incomplete. This is especially true if the TPS signal wire or other pins in the throttle body are still connected to the ECU or the throttle actuator control (TAC) module, which may cause the voltage to be pulled to 5V due to the way the system is designed.
In other words:
- With the pigtail disconnected, the system is no longer able to pull ground or make a proper reference for the signal, so the voltage could read as 5V (since some components like the ECU may still be outputting voltage to the sensor circuits).
- Pin G itself is meant to be a ground or signal return, so in normal operation with the pigtail connected, it should read 0V (ground) because it's part of the circuit. Without the pigtail, the ground circuit is not established, and you'll see an unusual voltage like 5V because of the floating signal.
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all run okay as it is. The DTC did not return since replacing the TPS, so we can call it resolved for now.
