Is this a new problem or has it always been this way since the swap was completed?
Sounds like a wiring issue. Did you wire the swap yourself or get a harness made?
Sounds like a wiring issue. Did you wire the swap yourself or get a harness made?
1 - 4 of 4 Posts
This is the document you want to look at for diagnosing P2135/P0121/P0123
These are all DTC's related to the accelerator pedal.
It is important to understand that the accelerator pedal and the throttle body are two separate systems. They have no direct connection. They are each wired separately to the ECU. When you have DTC's related to the accelerator pedal, replacing the throttle body does absolutely nothing. This is like clearing your throat to relieve constipation. Your oesophagus goes into your stomach. And your bowel comes out of your stomach. There is no direct connection. The pedal is wired to the ECU. The TB is wired to the ECU. No direct connection.
Follow the steps for diagnosing the pedal.
What you are experiencing is this failsafe:
![]()
One more thing. Always use the Toyota factory service manual for diagnosing DTC's. Never use generic DTC descriptions that you find on Google. The generic descriptions will almost always point you in the wrong direction.
And another thing. Nobody is ever thrilled about verifying voltages between a hard to reach component and the ECU. In some situations it's easier to just replace the part. Up to you really whether you replace your pedal, or test it first. The good news is you can look at the voltages in the live data of your scantool and you can see right away whether the pedal is putting out anything when you move it or whether it is putting out garbage or nothing at all.
These are all DTC's related to the accelerator pedal.
It is important to understand that the accelerator pedal and the throttle body are two separate systems. They have no direct connection. They are each wired separately to the ECU. When you have DTC's related to the accelerator pedal, replacing the throttle body does absolutely nothing. This is like clearing your throat to relieve constipation. Your oesophagus goes into your stomach. And your bowel comes out of your stomach. There is no direct connection. The pedal is wired to the ECU. The TB is wired to the ECU. No direct connection.
Follow the steps for diagnosing the pedal.
What you are experiencing is this failsafe:
One more thing. Always use the Toyota factory service manual for diagnosing DTC's. Never use generic DTC descriptions that you find on Google. The generic descriptions will almost always point you in the wrong direction.
And another thing. Nobody is ever thrilled about verifying voltages between a hard to reach component and the ECU. In some situations it's easier to just replace the part. Up to you really whether you replace your pedal, or test it first. The good news is you can look at the voltages in the live data of your scantool and you can see right away whether the pedal is putting out anything when you move it or whether it is putting out garbage or nothing at all.
1 - 4 of 4 Posts
