P0122 Throttle Position Sensor 1 circuit low

P0122 Throttle Position Sensor 1 circuit low - The TPS 1 sensor input voltage is below 0.25 volts for 0.07 seconds. When monitored with the ignition on, battery voltage greater than 6.98 volts. Default actions is the ETC light will illuminate, the MIL light will illuminate, if the vehicle is equipped with the stop/start feature, the system will be disabled when this DTC is active.

Possible causes P0122 code:

• TPS signal 1 circuit shorted to ground.
• TPS signal 1 circuit shorted to TPS sensor ground circuit.
• TPS signal 1 circuit shorted to the ETC motor (+) circuit.
• TPS signal 1 circuit shorted to the ETC motor (-) circuit.
• TPS signal 1 circuit open or high resistance.
• Throttle Body.
• Powertrain Control Module (PCM).

Diagnose code P0122 Throttle Position Sensor 1 circuit low

Step 1. Check active DTC

Diagnose and repair any system voltage 5-Volt reference DTC before continuing this test. Turn the ignition on, with the scan tool, read DTC.

Is the DTC active or pending?

Yes, go to step 3.

No, go to step 2.

Step 2. Throttle Follower Test

With the scan tool, perform the ETC Throttle Follower Test. Monitor the TPS 1 voltage, slowly press the accelerator pedal down.

Note : The voltage for TPS 1 should start at approximately 0.7 volts and increase to approximately 4.3 volts.

Is the TPS 1 voltage within the range of the listed specification?

Yes, perform the PCM intermittent condition.

No, go to step 3.

Step 3. Check the TPS 1 signal circuit for a short to ground

Turn the ignition off, disconnect the Throttle Body harness connector. Disconnect the PCM harness connector. Check for continuity between ground and the TPS 1 signal circuit at the TPS harness connector.

Is there continuity between ground and the TPS 1 signal circuit?

Yes, repair the TPS 1 signal circuit for a short to ground.

No, go to step 4.

Step 4. Check the TPS 1 signal circuit for a short to the TPS return circuit

Check for continuity between the TPS 1 signal circuit and the TPS return circuit at the Throttle Body harness connector.

Is there continuity between the TPS 1 signal circuit and the TPS return circuit?

Yes, repair the short between the TPS 1 signal circuit and the TPS return circuit.

No, go to step 5.

Step 5. Check the TPS 1 signal circuit for a short to the ETC motor (-) circuit

Check for continuity between the TPS 1 signal circuit and the ETC motor (-) circuit at the Throttle Body harness connector.

Is there continuity between the TPS 1 signal circuit and the ETC motor (-) circuit?

Yes, repair the short between the TPS 1 signal circuit and the ETC motor (-) circuit.

No, go to step 6.

Step 6. Check the TPS 1 signal circuit for a short to the ETC motor (+) circuit

Check for continuity between the TPS 1 signal circuit and the ETC motor (+) circuit at the Throttle Body harness connector.

Is there continuity between the TPS 1 signal circuit and the ETC motor (+) circuit?

Yes, repair the short between the TPS 1 signal circuit and the ETC motor (+) circuit.

No, go to step 7.

Step 7. Check the TPS signal circuit for an open/high resistance

Measure the resistance of the TPS 1 signal circuit between the Throttle Body harness connector and the PCM harness connector.

Is the resistance below 3.0 Ohms?

Yes, go to step 8.

No, repair the excessive resistance in the TPS 1 signal circuit.

Step 8. Throttle Position Sensor

Reconnect the PCM harness connector. Connect a jumper between the 5-Volt supply circuit and the TPS 1 signal circuit at the Throttle Body harness connector. Turn the ignition on, with the scan tool, read DTC. The P0123- THROTTLE POSITION SENSOR 1 CIRCUIT HIGH DTC should be active or pending with the jumper in place.

Does the scan tool display as described above?

Yes, verify that there is good pin to terminal contact in the Throttle Body and Powertrain Control Module (PCM) connectors. If no problems are found, replace the Throttle Body assembly.

No, go to step 9.

Step 9. Check related PCM and component connections

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