P0221-THROTTLE POSITION SENSOR 2 PERFORMANCE

For a complete wiring diagram, refer to the Wiring Information.

Theory of operation

The Electronic Throttle Control (ETC) system uses two Throttle Position Sensors (TPS) to monitor the throttle blade position. The Throttle Position Sensors 1 and 2 are located within the Throttle Body assembly. Each sensor has a 5-volt reference circuit, a low reference circuit, and a signal circuit. Processors are also used to monitor the ETC system data. The processors are located within the Powertrain Control Module (PCM). Each signal circuit provides the processors with a signal voltage proportional to throttle blade movement. The processors share and monitor data to verify that the indicated TPS calculation is correct.

When Monitored:
Ignition on and No MAP Sensor DTCs set.
Set Condition:
TP Sensor signals do not correlate to the MAP Sensor signal. Two Trip Fault. ETC light will illuminate. P2135 should set with this code also.

Possible Causes
EXCESSIVE RESISTANCE IN THE (K22) TP SENSOR NO.1
EXCESSIVE RESISTANCE IN THE (K122) TP SENSOR NO.2 SIGNAL CIRCUIT
EXCESSIVE RESISTANCE IN THE (F855) 5-VOLT SUPPLY CIRCUIT
EXCESSIVE RESISTANCE IN THE (K922) TP SENSOR RETURN CIRCUIT
(K22) TP SENSOR NO.1 SIGNAL CIRCUIT SHORTED TO THE (K122) TP SENSOR NO.2 SIGNAL CIRCUIT
THROTTLE POSITION SENSOR/THROTTLE BODY
POWERTRAIN CONTROL MODULE (PCM)

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

1. ACTIVE DIAGNOSTIC TROUBLE CODE (DTC)

NOTE: When this DTC is Active the engine speed, torque, and vehicle speed are limited to a Limp in mode.

NOTE: Diagnose any other TP Sensor DTCs before continuing.

NOTE: The throttle plate and linkage should be free from binding and carbon build up.

NOTE: Make sure the throttle plate is at the idle position.

NOTE: Inspect the engine for vacuum leaks.

1.	Ignition on, engine not running.

2.	With a scan tool, read the active DTCs.

Is the DTC Active at this time?

Yes

Go To 2

Go To 9

2. EXCESSIVE RESISTANCE IN THE (K122) TP SENSOR NO.2 SIGNAL CIRCUIT

1.	Turn the ignition off.

2.	Disconnect the PCM C2 harness connector.

3.	Using a Voltmeter, perform a voltage drop test. Back probe the (K122) TP Sensor No.2 Signal circuit at the Throttle Body harness connector and the PCM C2 harness connector. Make sure the Voltmeter leads are connected so a positive polarity is displayed on the Voltmeter.

WARNING:

When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury.

4.	Start the engine and allow it to reach normal operating temperature.

5.	Monitor the Voltmeter.

Is the voltage below 0.5 volt?

Yes

Go To 3

Repair the excessive resistance in the (K122) TP Sensor No.2 Signal circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

3. EXCESSIVE RESISTANCE IN THE (K22) TP SENSOR NO.1 SIGNAL CIRCUIT

1.	Turn the ignition off.

2.	Move the Voltmeter leads to back probe the (K22) TP Sensor No.1 Signal circuit at the Throttle Body harness connector and the PCM C2 harness connector. Make sure the Voltmeter leads are connected so a positive polarity is displayed on the Voltmeter.

WARNING:

3.	Start the engine and allow it to reach normal operating temperature.

4.	Monitor the Voltmeter.

Is the voltage below 0.5 Volt?

Yes

Go To 4

Repair the excessive resistance in the (K22) TP Sensor No.1 Signal circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

4. EXCESSIVE RESISTANCE IN THE (F855) 5-VOLT SUPPLY CIRCUIT

1.	Turn the ignition off.

2.	Move the Voltmeter leads to back probe the (F855) 5-volt Supply circuit at the Throttle Body harness connector and the PCM C2 harness connector. Make sure the Voltmeter leads are connected so a positive polarity is displayed on the Voltmeter.

WARNING:

3.	Start the engine and allow it to reach normal operating temperature.

4.	Monitor the Voltmeter.

Is the voltage below 0.5 volt?

Yes

Go To 5

Repair the excessive resistance in the (F855) 5-volt Supply circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

5. EXCESSIVE RESISTANCE IN THE (K922) TP SENSOR RETURN CIRCUIT

1.	Turn the ignition off.

2.	Move the Voltmeter leads to back probe the (K922) TP Sensor Return circuit at the Throttle Body harness connector and the PCM C2 harness connector. Make sure the Voltmeter leads are connected so a positive polarity is displayed on the Voltmeter.

WARNING:

3.	Start the engine and allow it to reach normal operating temperature.

4.	Monitor the Voltmeter.

Is the voltage below 0.5 volt?

Yes

Go To 6

Repair the excessive resistance in the (K922) TP Sensor Return circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

6. (K22) TP SENSOR NO.1 SIGNAL CIRCUIT SHORTED TO THE (K122) TP SENSOR NO.2 SIGNAL CIRCUIT

1.	Measure the resistance between the (K22) TP Sensor No.1 Signal circuit and the (K122) TP Sensor No.2 Signal circuit at the Throttle Body harness connector.

Is the resistance below 5.0 Ohms?

Yes

Repair the short between the (K122) TP Sensor No.2 Signal circuit and the (K22) TP Sensor No.1 Signal circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

Go To 7

7. THROTTLE POSITION SENSOR

1.	Turn the ignition off.

2.	Connect the PCM C2 harness connector.

3.	Ignition on, engine not running.

4.	Using the scan tool, monitor the TP Sensor No.1 and No.2 voltage.

5.	Connect a jumper wire between the (K922) TP Sensor Return circuit and the (K22) TP Sensor No.1 Signal circuit.

NOTE: TP Sensor No.1 voltage should change from approximately 4.7 volts to 0.3 volt.

6.	For TP Sensor No.2, connect a jumper wire between (F855) 5-Volt supply circuit and the (K122) TP Sensor No.2 Signal circuit.

NOTE: TP Sensor No.2 voltage should change from approximately 0 volts to 5.0 volts.

Is the voltage reading within the listed specification with the jumper wire installed?

Yes

Verify that there is good pin to terminal contact in the Throttle Body and Powertrain Control Module connectors. If OK, replace the Throttle Body Assembly. Disconnect the Battery when replacing the Throttle Body Assembly. After installation is complete, using a scan tool select the ETC RELEARN function. (Refer to 14 - Fuel System/Fuel Injection/THROTTLE BODY - Removal) .
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

Go To 8

NOTE: Remove the jumper wire before continuing.

8. POWERTRAIN CONTROL MODULE (PCM)

1.	Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Throttle Body and the Powertrain Control Module (PCM).

2.	Look for any chafed, pierced, pinched, or partially broken wires.

3.	Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Throttle Body and Powertrain Control Module connectors.

4.	Perform any Technical Service Bulletins that may apply.

Were there any problems found?

Yes

Repair as necessary.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

Replace and program the Powertrain Control Module in accordance with the service information. (Refer to 08 - Electrical/8E - Electronic Control Modules/MODULE, Powertrain Control - Removal) .
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

9. THROTTLE FOLLOWER TEST

1.	Ignition on, engine not running.

2.	Using the scan tool, perform the ETC Throttle Follower Test and monitor the TP Sensor No.1 or No.2 voltage.

3.	Slowly press the throttle pedal down.

4.	The voltage for TP Sensor No.1 should start at approximately 0.7 volt and increase to approximately 4.3 volts.

5.	The voltage for TP Sensor No.2 should start at approximately 4.3 volts and decrease to approximately 0.7 volt.

Is the voltage within the range of the listed specification for the appropriate Sensor?

Yes

Perform the INTERMITTENT CONDITION diagnostic procedure. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

Verify that there is good pin to terminal contact in the Throttle Body and Powertrain Control Module connectors. If OK, replace the Throttle Body Assembly. Disconnect the Battery when replacing the Throttle Body Assembly. After installation is complete, using a scan tool select the ETC RELEARN function. (Refer to 14 - Fuel System/Fuel Injection/THROTTLE BODY - Removal) .
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

P0221-THROTTLE POSITION SENSOR 2 PERFORMANCE

Theory of operation

Possible Causes