Circuit Description
The throttle position (TP) sensor is mounted on the throttle body/TAC assembly. The sensor is actually two individual throttle position sensors within one housing. Two separate signal, ground and reference circuits are used in order to connect the TP sensor assembly and the throttle actuator control (TAC) module. Each TP sensor signal voltage increases as the throttle opens. The signal circuit for TP sensors are pulled up to reference voltage.
Conditions for Running the DTC
| • | DTCs P0606, P1517, P1518 are not set. |
| • | The ignition switch is in the crank or run position. |
| • | The ETC serial data is operational. |
Conditions for Setting the DTC
TP sensor 1 and TP sensor 2 disagree by more than 0.17 volts.
Action Taken When the DTC Sets
| • | The PCM will illuminate the malfunction indicator lamp (MIL) during the first trip in which the diagnostic runs and fails. |
| • | If equipped with traction control, the PCM will command the EBTCM via the serial data circuit to turn OFF traction control and illuminate the TRACTION OFF lamp. |
| • | The PCM will store conditions which were present when the DTC set as Freeze Frame/Failure Records data. |
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
When the TAC module detects a problem within the ETC System the PCM receives a message across serial data and more than one ETC System related DTC may set. This is due to the many redundant tests run continuously on this system. Locating and repairing one individual problem may correct more than one DTC. Keep this in mind when reviewing captured DTC info.
Inspect for the following:
Many situations may lead to an intermittent condition. Perform each inspection or test as directed.
Important: : Remove any debris from the connector surfaces before servicing a component. Inspect the connector gaskets when diagnosing or replacing a component. Ensure that the gaskets are installed correctly. The gaskets prevent contaminate intrusion.
| • | Loose terminal connection |
| - | Use a corresponding mating terminal to test for proper tension. Refer to Testing for Intermittent Conditions and Poor Connections , and to Connector Repairs in Wiring Systems for diagnosis and repair. |
| - | Inspect the harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and faulty terminal to wire connection. Refer to Testing for Intermittent Conditions and Poor Connections , and to Connector Repairs in Wiring Systems for diagnosis and repair. |
| • | Damaged harness--Inspect the wiring harness for damage. If the harness inspection does not reveal a problem, observe the display on the scan tool while moving connectors and wiring harnesses related to the sensor. A change in the scan tool display may indicate the location of the fault. Refer to Wiring Repairs in Wiring Systems for diagnosis and repair. |
| • | Inspect the powertrain control module (PCM) and the engine grounds for clean and secure connections. Refer to Wiring Repairs in Wiring Systems for diagnosis and repair. |
If the condition is determined to be intermittent, reviewing the Snapshot or Freeze Frame/Failure Records may be useful in determining when the DTC or condition was identified.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
1 | Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? | -- | ||
2 |
Important: If DTC P1518, 1120 or 1220 are also set, refer to those DTCs first for further diagnosis.
Does the scan tool indicate NO? | -- | ||
3 |
Does the harness movement cause this DTC to fail this ignition? | -- | Go to Diagnostic Aids | |
4 |
Does the voltage measure within the specified range? | 3.9-4.6 V | ||
5 | Measure the voltage on both the TP 1 and TP 2 signal circuits using a DMM that is connected to a good ground. Does the voltage measure within the specified range? | 3.9-4.6 V | ||
6 | Measure for continuity between the TP 1 reference and the TP 2 reference at the TAC using a DMM. Does the DMM indicate continuity? | -- | ||
7 | Measure for continuity between the TP 1 signal and the TP 2 signal at the TAC using a DMM. Does the DMM indicate continuity? | -- | ||
8 |
Does the DMM indicate continuity? | -- | ||
9 | Measure for continuity between the TP 1 signal and the TP 2 signal at the TAC module harness connector using a DMM. Does the DMM indicate continuity? | -- | ||
10 | Repair the harness/connections as necessary. Refer to Wiring Repairs and Connector Repairs in Wiring Systems. Did you complete the repair? | -- | -- | |
11 | Repair the short to voltage in the reference circuit. Refer to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | ||
12 | Repair the short to voltage in the signal circuit. Refer to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | ||
13 | Replace the throttle body/TAC assembly. Refer to Throttle Body Assembly Replacement . Did you complete the replacement? | -- | -- | |
14 | Replace the TAC module. Refer to Accelerator Pedal Replacement . Did you complete the replacement? | -- | -- | |
15 | Repair the TP 1 and TP 2 reference circuits shorted together. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | -- | |
16 | Repair the TP 1 and TP 2 signal circuits shorted together. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | -- | |
17 |
Does the DTC reset? | -- | ||
Does the scan tool indicate any DTCs set that you have not diagnosed? | -- | Go to applicable DTC | System OK |
