Symptoms
Potential
Symptoms of a P2126 trouble code may include:
- Illumination of the Malfunction Indicator Lamp (MIL) (Check Engine light or Service Engine Soon light)
- Intermittent stumbling during acceleration or deceleration
- Black smoke puff during acceleration
- No start condition
Causes
A P2126 code may indicate that one or more of the following events has occurred:
- TPS has an intermittent open or short internally
- Harness rubbing causing an open or short in the wiring
- Poor connection at the TPS
- Faulty PCM (less likely)
- Water or corrosion in the connector or sensor
Possible Solutions
1. If you have access to a scan tool, check the idle and WOT (wide open throttle) readings for the TPS. Verify if they are close to the specifications mentioned above. If not, replace the TPS and recheck.
2. Look for an intermittent open or short in the TPS signal. To do this, you cannot use a scan tool. You will need an oscilloscope. The reason is that scan tools sample many different readings over one or two data lines and may miss an intermittent interruption. Connect your oscilloscope and observe the signal. It should sweep smoothly up and down without jerks or spikes.
3. If no issues were found, perform a wiggle test. To do this, wiggle the connector and harness while observing the pattern. Does it drop out? If yes, replace the TPS and recheck.
4. If you have no TPS signal, check for the 5-volt reference at the connector. If present, check if the ground circuit is open or shorted.
5. Ensure the signal circuit is not at 12V. It should never have battery voltage. If it does, trace the circuit for a short and repair.
6. Look for water in the connector and replace the TPS if necessary.