Circuit Description
The throttle position (TP) sensor is mounted on the throttle body of the throttle actuator control (TAC) assembly. The sensor is actually 2 individual throttle position sensors within 1 housing. Two separate signal circuits, a low reference circuit and a 5-volt reference circuit, are used in order to connect the TP sensor assembly and the throttle actuator control module. Each TP sensor signal voltage increases as the throttle opens. The signal circuit for TP sensors are pulled up to 5-volt reference voltage.
Conditions for Running the DTC
| • | DTCs P0606, P1517, or P1518 are not set. |
| • | The ignition switch is in the crank or run position. |
| • | The electronic throttle control (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 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/Failure Records. |
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. |
Diagnostic Aids
When the TAC module detects a condition within the electronic throttle control (ETC) system, the powertrain control module (PCM) receives a message across serial data, and more than 1 ETC system related DTC may set. This condition is due to the many redundant tests that run continuously on this system. Locating and repairing 1 individual condition may correct more than 1 DTC. Be aware of this condition when you review the captured DTC info.
If the condition is intermittent, refer to Intermittent Conditions .
Test Description
The number below refers to the step number on the diagnostic table.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics | ||||
1 | Did you perform the Diagnostic System Check-Engine Controls? | -- | Go to Step 2 | |
2 |
Important: If DTCs P1518, P1120 or P1220 are also set, refer to those DTCs first for further diagnosis.
Does the scan tool indicate Agree? | -- | Go to Step 3 | Go to Step 4 |
3 |
Does the harness movement cause this DTC to fail this ignition? | -- | Go to Step 10 | Go to Diagnostic Aids |
4 |
Does the voltage measure within the specified values? | 3.9-4.6 V | Go to Step 5 | Go to Step 11 |
5 | Measure the voltage on both the TP 1 and the TP 2 signal circuits using a DMM that is connected to a good ground. Does the voltage measure within the specified values? | 3.9-4.6 V | Go to Step 6 | Go to Step 12 |
6 |
Does the DMM indicate continuity? | -- | Go to Step 13 | Go to Step 7 |
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? | -- | Go to Step 13 | Go to Step 8 |
8 |
Does the DMM indicate continuity? | -- | Go to Step 15 | Go to Step 9 |
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? | -- | Go to Step 16 | Go to Step 14 |
10 | Repair the harness and connections as necessary. Refer to Wiring Repairs , and to Connector Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 17 | -- |
11 | Repair the short to voltage in the 5-volt reference circuit. Refer to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 17 | Go to Step 14 |
12 | Repair the short to voltage in the signal circuit. Refer to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 17 | Go to Step 14 |
13 | Replace the throttle body of the TAC assembly. Refer to Throttle Body Assembly Replacement . Did you complete the replacement? | -- | Go to Step 17 | -- |
14 | Replace the TAC module. Refer to Accelerator Pedal Position Sensor Replacement . Did you complete the replacement? | -- | Go to Step 17 | -- |
15 | Repair the TP 1 and the TP 2 5-volt reference circuits that are shorted together. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 17 | -- |
16 | Repair the TP 1 and TP 2 signal circuits that are shorted together. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 17 | -- |
17 |
Does the DTC run and pass? | -- | Go to Step 18 | Go to Step 2 |
With a scan tool, observe the stored information, Capture Info. Does the scan tool display any DTCs that you have not diagnosed? | -- | System OK | ||
