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P2135






P2135-THROTTLE POSITION SENSOR 1/2 CORRELATION

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





Theory of Operation

The Electronic Throttle Control (ETC) system uses two Accelerator Pedal Position (APP) Sensors to monitor the accelerator pedal position. The APP Sensors 1 and 2 are integrated into one assembly located at the pedal assembly. Each sensor has a 5-volt reference circuit, a low reference circuit, and a signal circuit. The Powertrain Control Module (PCM) reads the two signals individually and then compares the two signals as a redundant check of the throttle position. One of the sensors will fluctuate between 0 volts and 5.0 volts and the other sensor will fluctuate between 0 volts and 2.5 volts. The fluctuation of the two sensors should move proportionately. E.G. When operating properly, the voltage reading of the sensor operating on the 5.0 volt scale will always approximately two time the voltage reading of the sensor on the 2.5 volts scale.

- When Monitored:
With the ignition on and no other Throttle Position Sensor 1 or Throttle Position Sensor 2 circuit low or circuit high DTCs present.

- Set Condition:
The Powertrain Control Module (PCM) compares the signals from Throttle Position Sensor 1 and Throttle Position Sensor 2, and determines a difference between the two inputs of 5 degrees. One trip fault. ETC light is illuminated.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.

Diagnostic Test

1. ACTIVE DTC

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

1. Turn the ignition on.
2. With a scan tool, read the active DTCs.

Is the DTC Active at this time?

Yes

- Go To 2

No

- Go To 7

2. CHECK FOR EXCESSIVE RESISTANCE IN THE (K22) TPS 1 SIGNAL CIRCUIT
1. Turn the ignition off.
2. Disconnect the Throttle Body harness connector.
3. Disconnect the PCM C2 harness connector.
4. Measure the resistance of the (K22) TPS 1 Signal circuit between the Throttle Body harness connector and the PCM C1 harness connector.

Is the resistance below 5.0 Ohms?

Yes

- Go To 3

No

- Repair the excessive resistance in the (K22) TPS 1 Signal circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

3. CHECK FOR EXCESSIVE RESISTANCE IN THE (K122) TPS 2 SIGNAL CIRCUIT
1. Measure the resistance of the (K122) TPS 2 Signal circuit between the Throttle Body harness connector and the PCM C1 harness connector.

Is the resistance below 5.0 Ohms?

Yes

- Go To 4

No

- Repair the excessive resistance in the (K122) TPS 2 Signal circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

4. CHECK FOR EXCESSIVE RESISTANCE IN THE (K922) TPS RETURN CIRCUIT
1. Measure the resistance of the (K922) TPS 1 Return circuit between the Throttle Body harness connector and the PCM C1 harness connector.

Is the resistance below 5.0 Ohms?

Yes

- Go To 5

No

- Repair the excessive resistance in the (K922) TP Sensor Return circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

5. CHECK FOR EXCESSIVE RESISTANCE IN THE (F855) 5-VOLT SUPPLY CIRCUIT
1. Measure the resistance of the (F855) 5-Volt Supply circuit between the Throttle Body harness connector and the PCM C1 harness connector.

Is the resistance below 5.0 Ohms?

Yes

- Go To 6

No

- Repair the excessive resistance in the (F855) 5-Volt Supply circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

6. 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. Powertrain Verification Test.

No

- Replace and program the Powertrain Control Module. .
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

7. THROTTLE FOLLOWER TEST
1. Ignition on, engine not running.
2. With a 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 TPS 1 should start at approximately 0.7 volts and increase to approximately 4.3 volts.
5. The voltage for TPS 2 should start at approximately 4.3 volts and decrease to approximately 0.7 volts.

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

Yes

- Perform the INTERMITTENT CONDITION diagnostic procedure. Intermittent Condition Test.

No

- Verify that there is good pin to terminal contact in the Throttle Body and Powertrain Control Module connectors. If OK, disconnect the Battery when replacing the Throttle Body Assembly. Replace the Throttle Body Assembly. . After installation is complete, use a scan tool and the Throttle Body Self Learning procedure.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

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