For 1990-2009 cars

### Circuit Description

The throttle actuator control (TAC) assembly has 2 throttle position (TP) sensors mounted within the assembly. The powertrain control module (PCM) provides individual signal, ground, and 5-volt reference circuits to each sensor. Both sensors operate within a voltage range between 0.35-4.65 volts. When the throttle is opened from 0-100 percent, one sensor signal voltage increases while the other decreases. The signal circuit for TP sensor 1 is referenced to ground, and the signal circuit for TP sensor 2 is pulled up to 5 volts within the PCM.

### DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P2135 Throttle Position (TP) Sensor 1-2 Correlation

### Conditions for Running the DTC

• | The ignition is ON.

• | DTCs P0120, P0220, P0641, P0651 are not set.

• | The ignition voltage is greater than 5.23 volts.

• | DTC P2135 runs continuously when the above conditions are met.

### Conditions for Setting the DTC

The difference between the TP sensor 1 and the TP sensor 2 exceeds a predetermined value for more than 2 seconds.

### 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 PCM will turn OFF the malfunction indicator lamp (MIL) during the third consecutive trip in which the diagnostic has run and passed.

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

• | The DTC can be cleared by using a scan tool.

### Diagnostic Aids

If the DTC is determined to be intermittent, refer to Intermittent Conditions.

### Test Description

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

1. This step tests the integrity of the 5-volt reference and ground circuits of the TP sensors.

2. This step determines if the 5-volt reference circuit or the sensor ground circuit is the cause of the DTC.

3. If the scan tool displays 100 percent for the TP sensor 1 and the TP sensor 2 angle, this indicates that the TP sensor signal circuits are not the cause of the DTC.

4. This step tests for excessive resistance in the TP sensor 5-volt reference circuit between the TP sensor harness connector and the PCM harness connector.

5. This step tests for excessive resistance in the TP sensor ground circuit between the TP sensor harness connector and the PCM harness connector.

6. This step tests for the TP sensor signal circuits for being shorted to another circuit in the PCM wiring harness between the PCM and the TP sensor wiring harness.

7. When the PCM detects a condition within the throttle control system, more than one related DTC may set. This is due to the many redundant tests run continuously on this system. Locating and repairing one individual condition may correct more than one DTC. Keep this in mind when reviewing captured DTC info.

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | Go to Diagnostic System Check - Vehicle
2 | Observe the DTC information with a scan tool. Is DTC P0641 or P0651 also set? | -- | Go to Diagnostic Trouble Code (DTC) List - Vehicle | Go to Step 3
3 |

1. Turn ON the ignition, with the engine OFF.
2. Monitor the throttle position (TP) sensors Agree/Disagree parameter using the scan tool.

Does the scan tool indicate Disagree?

--

Go to Step 6

Go to Step 4

4 |

1. Remove the resonator assembly from the throttle body assembly.

Important: Removing the ETC fuse will set additional DTCs.

2. Remove the ETC fuse.
3. Open the throttle blade to wide open throttle (WOT) by hand, then return it to closed throttle. Stop briefly at approximately 25 percent, 50 percent, 75 percent and 100 percent in each direction. Test the Throttle Sensors Disagree parameter at each stop.

Does the scan tool indicate Disagree while rotating the throttle blade?

--

Go to Step 6

Go to Step 5

5 |

1. Observe the Freeze Frame/Failure Records for this DTC.
2. Turn OFF the ignition for 30 seconds.
3. Start the engine.
4. 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.

Does the DTC fail this ignition?

--

Go to Step 15

Go to Intermittent Conditions

6 |

1. Disconnect the TP sensor electrical connector.
2. Turn ON the ignition, with the engine OFF.
3. Measure the voltage between the 5-volt reference circuit of TP sensor 1 and the TP sensor 1 low reference circuit with a DMM.
4. Measure the voltage between the 5-volt reference circuit of TP sensor 2 and the TP sensor 2 low reference circuit with a DMM.

Does the DMM display a voltage within the specified range for both measurements?

4.9-5.1 V

Go to Step 8

Go to Step 7

7 | Measure the voltage on the 5-volt reference circuit for TP sensor 1 and TP sensor 2 to a battery ground with a DMM. Does the DMM display a voltage within the specified range? | 4.9-5.1 V | Go to Step 10 | Go to Step 9
8 | Observe the TP sensor 1 and TP sensor 2 angle on the scan tool. Does the scan tool indicate both sensors at the specified value? | 100% | Go to Step 12 | Go to Step 11
9 | Test the 5-volt reference circuit of the TP sensor 1 and TP sensor 2 for high resistance. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 13
10 | Test the low reference circuit of the TP sensor 1 and TP sensor 2 for high resistance. Refer to Circuit Testing and Wiring Repairs. Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 13
11 | Test the signal circuit of the TP sensor 1 and TP sensor 2 for an open or for high resistance. Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 13
12 | Replace the throttle body assembly. Refer to Throttle Body Assembly Replacement . Did you complete the replacement? | -- | Go to Step 15 | --
13 | Test for poor connections and/or terminal tension at the TP sensor and at the powertrain control module (PCM). Refer to Testing for Intermittent Conditions and Poor Connections. Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 14
14 | Replace the PCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 15 | --
15 |

1. Clear the DTCs with a scan tool.
2. Turn OFF the ignition for 30 seconds.
3. Start the engine.
4. 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 16

16 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | -- | Go to Diagnostic Trouble Code (DTC) List - Vehicle | System OK