Car Fix DIY Videos

GMC Terrain 2009 with a customer complaint of the check engine and traction control lights being on. and the engine is not revving up properly Let’s hook up the scan tool and see what we have.

it looks like there are a few DTC codes related to the throttle body. The first code is P2101, which indicates a problem with the control module throttle actuator position performance.
The second code, P2119, suggests an issue with the throttle closed position performance. Lastly, P0121 is related to the Throttle Position TP Sensor 1. All of these codes point towards a problem with the throttle body.

Let’s go to the data list and check the live data, it’s clear that there is an issue with TP 1. The reading is fluctuating up and down, which indicates a problem with the Throttle Position Sensor 1. This sensor is responsible for transmitting the throttle position to the engine control module, and if it’s not functioning properly, it can cause issues with engine performance and drivability.

Checking the wiring schematic is a good idea before performing an intrusive test. It can help ensure that the test is performed correctly and that the correct wires are being tested.
our target is the throttle body connector PIN 2 green wire

Okay, now I will back probe PIN 2 and measure the voltage. The voltage reading is steady at 4.2 volts, while the scan tool data fluctuates. This points towards an issue with the Engine Control Module (ECM). The ECM is located at the side of the battery

My call was for a new ECM but is not available, I bought this used ECM now I will install it and perform programming

OK, now is the moment of true It’s important to clear any existing DTCs after performing programming to ensure that any old or irrelevant codes are removed. Back to live data to check if the issue has been resolved. If there are no new DTCs and the live data shows that the TP 1 is no longer fluctuating, then it’s likely that the used ECM has resolved the issue

It’s always important to verify that any repairs have resolved the issue by rechecking for any DTCs and ensuring that the live data shows that the TP 1 is steady