DTC P0222. Cadillac STS 2005

For 1990-2009 cars only

Makes 🢒 Cadillac 🢒 2005 🢒 STS 🢒 Accessories 🢒 Navigation Systems 🢒 DTC P0222

Circuit Description

The throttle position (TP) sensors 1 and 2 are located within the throttle body assembly. The TP sensors share a common 5-volt reference circuit and a common low reference circuit. The 5-volt reference circuit is also shared with accelerator pedal position (APP) sensor 2. The 5-volt reference voltage is supplied on 2 separate engine control module (ECM) terminals, but the terminals are connected internally to the same voltage supply. Each TP sensor has an individual signal circuit, which provides the ECM with a signal voltage proportional to throttle the plate movement. When the throttle plate is in the closed position, the TP sensor 1 signal voltage is near the low reference and increases as the throttle plate is opened. TP sensor 2 signal voltage at closed throttle is near the 5-volt reference and decreases as the throttle plate is opened. If the ECM detects the TP sensor 2 signal voltage is less than 0.47 volts, DTC P0222 sets.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0222 Throttle Position (TP) Sensor 2 Circuit Low Voltage

Conditions for Running the DTC

•	The battery voltage is more than 10 volts.

•	The ignition is ON.

•	DTC P0222 runs continuously once the above conditions are met.

Conditions for Setting the DTC

The TP sensor 2 voltage is less than 0.47 volts for more than 300 milliseconds.

Action Taken When the DTC Sets

•	The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.

•	The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame and/or the Failure Records.

•	The control module commands the TAC system to operate in the Reduced Engine Power mode.

•	A message center or an indicator displays Reduced Engine Power.

•	Under certain conditions the control module commands the engine OFF.

Conditions for Clearing the MIL/DTC

•	The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.

•	A current DTC, Last Test Failed, clears when the diagnostic runs and passes.

•	A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.

•	Clear the MIL and the DTC with a scan tool.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

The ECM performs a comparison of the signals from both TP sensors during the entire range of operation. If the DTC does not set with the key ON and the accelerator pedal released, actuating the throttle may cause the DTC to set.

This step tests for the proper operation of the TP sensor 2 signal circuit. The ECM supplies a pull up voltage of about 4.8 volts on the signal circuit.

The 5-volt reference for the TP sensors and the APP sensor 2 are connected inside the ECM. This step is to determine if the APP sensor is affecting the 5-volt reference circuit of the TP sensors.

Step

Action

Value

Yes

Schematic Reference: Engine Controls Schematics

Connector End View Reference: Engine Control Module Connector End Views or Engine Controls Connector End Views

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

Turn ON the ignition, with the engine OFF.
Observe the throttle position (TP) sensor 2 parameter with a scan tool.

Is the TP sensor 2 voltage less than the specified value?

0.5 V

Go to Step 5

Go to Step 3

Observe the Freeze Frame/Failure Records data for this DTC.
Turn OFF the ignition for 30 seconds.
Start the engine.
Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze/Frame Failure Records.

Did the DTC fail this ignition?

Go to Step 5

Go to Step 4

Clear the DTCs with a scan tool.
Slowly depress the accelerator pedal to wide open throttle (WOT) and then slowly return it to the closed position.
Repeat this action several times.

Did the DTC fail this ignition?

Go to Step 14

Go to Intermittent Conditions

Turn OFF the ignition.
Disconnect the throttle body harness connector.
Turn ON the ignition, with the engine OFF.
Measure the voltage from the 5-volt reference circuit of the TP sensors to a good ground with a DMM.

Is the voltage within the specified range?

4.8-5.2 V

Go to Step 6

Go to Step 7

Turn OFF the ignition.
Connect a 3-amp fused jumper wire between the 5-volt reference circuit of the TP sensor and the signal circuit of the TP sensor 2.
Turn ON the ignition, with the engine OFF.
Observe the TP sensor 2 parameter with a scan tool.

Is the voltage within the specified range?

4.8-5.2 V

Go to Step 11

Go to Step 9

Turn OFF the ignition.
Disconnect the accelerator pedal position (APP) sensor harness connector.
Turn ON the ignition, with the engine OFF.
Measure the voltage from the 5-volt reference circuit of the TP sensors to a good ground with the DMM.

Is the voltage within the specified range?

4.8-5.2 V

Go to Step 13

Go to Step 8

Test the 5-volt reference circuit of the TP sensors for the following conditions:

•	A short to ground

•	High resistance

•	An open circuit

Did you find and correct the condition?

Go to Step 16

Go to Step 10

Test the signal circuit of the TP sensor 2 for the following conditions:

•	A short to ground

•	A short to the low reference circuit

•	High resistance

•	An open circuit

Repair as necessary. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 16

Go to Step 12

Test the 5-volt reference circuit of the APP sensor 2 for a short to ground. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 16

Go to Step 12

Test for an intermittent and for a poor connection at the throttle body. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 16

Go to Step 14

Test for an intermittent and for a poor connection at the engine control module (ECM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 16

Go to Step 15

Replace the APP sensor. Refer to Accelerator Pedal Position Sensor Replacement .

Did you complete the replacement?

Go to Step 16

Replace the throttle body assembly. Refer to Throttle Body Assembly Replacement .

Did you complete the replacement?

Go to Step 16

Replace the ECM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 16

Clear the DTCs with a scan tool.
Turn OFF the ignition for 30 seconds.
Start the engine.
Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze/Frame Failure Records.

Did the DTC fail this ignition?

Go to Step 2

Go to Step 17

Observe the Capture Info with a scan tool. More than one throttle actuator control (TAC) system-related DTC may set. This is due to the many redundant tests ran continuously on this system. Locating and repairing one individual condition may correct more than one DTC. Be aware of this when reviewing the Capture Info.

Are there any DTCs that have not been diagnosed?

Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information

System OK