DTC P0123 Throttle Position (TP)Sensor Circuit High Voltage. Cadillac Seville 2000

For 1990-2009 cars only

Makes 🢒 Cadillac 🢒 2000 🢒 Seville 🢒 DTC 🢒 DTC P0123 Throttle Position (TP)Sensor Circuit High Voltage

Engine Controls Component Views
Sensors
OBD II Symbol Description Notice
Handling ESD Sensitive Parts Notice

Circuit Description

The throttle position (TP) sensor is potentiometer used to indicate the amount of throttle opening. The PCM supplies the TP sensor with a 5 volt reference and a ground. The TP sensor provides a signal voltage to the PCM relative to throttle blade angle. With the throttle closed, the signal voltage is low. However, the signal voltage increases as the throttle opens. During normal operation, TP signal voltage will vary from below 1 volt at idle to above 4 volts at wide open throttle (WOT). The TP signal is one of the most important sensor inputs used by the PCM for controlling fuel and most of the PCM-controlled outputs. If the PCM detects an excessively high TP sensor signal, DTC P0123 will set.

Conditions for Running the DTC

•	The engine is running.

•	IAC valve position is between 10-110 counts.

Conditions for Setting the DTC

•	The TP sensor signal voltage is more than 4.8 volts.

•	The condition exists for less than 1 second.

Action Taken When the DTC Sets

•	The PCM illuminates the malfunction indicator lamp (MIL) during the second consecutive trip in which the diagnostic test runs and fails.

•	The PCM stores the conditions present when the DTC set as Freeze Frame/Failure Records data.

Conditions for Clearing the MIL/DTC

•	The PCM will turn the MIL OFF after the third consecutive trip in which the diagnostic runs and passes.

•	The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.

•	The DTC can be cleared by using the scan tool Clear DTC Information function.

Diagnostic Aids

If the condition is intermittent, refer to DTC P1121 Throttle Position (TP) Sensor Circuit Intermittent High Voltage and/or Intermittent Conditions .

Step

Action

Values

Yes

Did you perform the Powertrain On Board Diagnostic (OBD) System Check?

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

Is DTC P1635 also set?

Go to DTC P1635 5 Volt Reference Circuit

Go to Step 3

Turn ON the ignition, with the engine OFF.
Observe the TP sensor display on the scan tool.

Does the scan tool indicate a TP sensor voltage near the specified value?

0.5V

Go to Diagnostic Aids

Go to Step 4

Turn OFF the ignition.
Disconnect the TP sensor connector.
Turn ON the ignition, with the engine OFF.
Observe the TP sensor display on the scan tool.

Does the scan tool indicate a TP sensor voltage near the specified value?

Go to Step 5

Go to Step 6

Test the TP sensor ground for the following conditions:

•

Open

•	Poor connections at the TP sensor

•	Poor connections at the PCM

If a conditions is found, repair as necessary. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 9

Go to Step 7

Turn OFF the ignition.
Disconnect the PCM connector C1. Refer to Powertrain Control Module Replacement/Programming .
Turn ON the ignition, with the engine OFF.
Test the TP signal circuit for a short to voltage or the 5V Reference circuit. Refer to Circuit Testing in Wiring Systems.
If a condition is found, repair as necessary. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 9

Go to Step 8

Replace the TP sensor. Refer to Throttle Position Sensor Replacement .

Is the action complete?

Go to Step 9

Important: The replacement PCM must be programmed.

Replace the PCM. Refer to Powertrain Control Module Replacement/Programming .

Is the action complete?

Go to Step 9

Review and record the scan tool Fail Records data.
Operate the vehicle within the parameters listed in the Conditions for Running the DTC.
With the scan tool, monitor the Specific DTC Information for DTC P0123 until the test runs.

Does the scan tool indicate that DTC P0123 passed?

System OK

Go to Step 2