Schematic Reference: Engine Controls Schematics
Circuit Description
The throttle position (TP) sensor has a closed throttle position (CTP) switch that sends a signal to the Engine Control Module (ECM). The ECM applies 5 volts to the CTP switch. The CTP switch is closed when the throttle valve is closed, and the CTP switch is open when the throttle valve is open. The ECM receives a low voltage signal from the CTP switch when the engine is idling, and receives a high voltage signal from the CTP switch when the engine is above idle.
Conditions for Setting the DTC
The following conditions are present for 10 seconds, and occur 3 times.
| • | High voltage input at the ECM indicated with the engine running at idle. |
| • | Engine speed is less than 1000 RPM. |
| • | The CTP switch is open (Not Idle). |
OR
The following conditions are present for 3 seconds.
| • | Greater than 30° throttle valve opening. |
| • | Engine speed is greater than 2300 RPM. |
| • | The CTP switch is closed (Idle). |
| • | Engine load greater than 40%. |
Action Taken When the DTC Sets
| • | The malfunction indicator lamp (MIL) will illuminate. |
| • | The ECM will record operating conditions at the time the diagnostic fails. This information will be stored in the Freeze Frame buffer. |
Conditions for Clearing the MIL/DTC
| • | The MIL will turn off after three consecutive drive cycles without a fault present. |
| • | A DTC will clear after 40 consecutive warm-up cycles without a fault. |
| • | The DTCs can be cleared by using a scan tool or by disconnecting the ECM battery feed. |
Diagnostic Aids
An intermittent malfunction may be caused by a fault in the TP sensor circuit. Inspect the wiring harness and components for any of the following conditions:
| • | Backed out terminals. |
| • | Improper mating of terminals. |
| • | Broken electrical connector locks. |
| • | Improperly formed or damaged terminals. |
| • | Faulty terminal to wire connections. |
| • | Physical damage to the wiring harness. |
| • | A broken wire inside the insulation. |
| • | Corrosion of electrical connections, splices, or terminals. |
An incorrectly adjusted TP sensor could cause a DTC P0510 to set. Refer to Throttle Position Sensor Adjustment
If the DTC P0510 cannot be duplicated, the information included in the Freeze Frame data can be useful in determining vehicle operating conditions since the DTC was first set.
Test Description
The numbers below refer to the step numbers in the Diagnostic Table.
-
The Powertrain (OBD) System Check prompts the technician to complete some basic checks and store the Freeze Frame data on the scan tool if applicable. This creates an electronic copy of the data taken when the fault occurred. The information is then stored in the scan tool for later reference.
-
Review the Freeze Frame data to determine when the DTC set. Always record this information.
-
The CTP switch is located inside the TP sensor. Replace the TP sensor in order service a faulty CTP switch.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | |||
2 |
Did the CTP switch fail either test? | -- | ||
3 |
Does the scan tool indicate a P0510? | -- | Go to Diagnostic Aids | |
Is the voltage between the specified value? | 4 to 6 volts | |||
Probe the TP sensor ground circuit, with a test light connected to B+. Did the test light illuminate? | -- | |||
6 |
Was a repair necessary? | -- | ||
7 |
Was a repair necessary? | -- | ||
8 | Adjust or replace the TP sensor. Refer to Throttle Position Sensor Adjustment or Throttle Position Sensor Replacement. Is the action complete? | -- | -- | |
9 | Replace the ECM. Refer to Engine Control Module Replacement. Is the action complete? | -- | -- | |
10 |
Are any DTCs displayed on the scan tool? | -- | Go to the Applicable DTC Table | System OK |
