Circuit Description
The Powertrain Control Module (PCM) supplies a 5.0 volt reference signal and a ground to the sensor. The TP sensor sends a voltage signal back to the PCM relative to the throttle plate opening. The voltage will vary from approximately 0.35 volt at closed throttle, to over 4.65 volts at wide open throttle (WOT).
Conditions For Running The DTC
The engine is running.
Conditions for Setting the DTC
The TP sensor reads less than 0.10 volt for 6.25 seconds.
Action Taken When the DTC Sets
| • | The malfunction indicator lamp (MIL) will illuminate after two consecutive ignition cycles in which the diagnostic runs with the fault active. |
| • | The PCM will record the operating conditions at the time that the diagnostic fails. This information will store in the Freeze Frame and Failure Records buffers. |
| • | A history DTC stores. |
| • | The coolant fan turns ON. |
| • | The TP angle will default to 0 percent when the vehicle speed is less than 3 km/h (2 mph) and 10 percent when the vehicle speed is more than 3 km/h (2 mph). The scan tool will display the defaulted value. |
Conditions for Clearing the MIL/DTC
| • | The MIL will turn OFF after three consecutive ignition cycles in which the diagnostic runs without a fault. |
| • | A history DTC will clear after 40 consecutive warm-up cycles without a fault. |
| • | Use a scan tool to clear the DTCs. |
Diagnostic Aids
The scan tool reads the throttle position (TP) in volts. The TP should read approximately 0.35-0.85 volts with the throttle closed and the ignition ON or at idle. The voltage should increase at a steady rate as the throttle is moved toward wide open throttle (WOT).
The scan tool will also read the throttle angle percentage, from 0 percent at closed throttle to 100 percent at wide open throttle.
Refer to Diagnostic Starting Point .
Scan the TP sensor signal while depressing the accelerator pedal with the ignition turned ON, leaving the engine OFF. The display should vary from less than 1.25 volts (1250 mV) when the throttle was closed to more than 4.5 volts (4500 mV) when the throttle is held at the wide open throttle (WOT) position.
An intermittent may be caused by any of the following conditions:
| • | A faulty connection |
| • | Rubbed-through wire insulation |
| • | A broken wire inside the insulation |
Thoroughly inspect any circuitry that is suspected of causing the intermittent complaint. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
If a repair is necessary, then refer to Wiring Repairs or Connector Repairs in Wiring Systems.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
If the TP signal measures less than 0.25 volt, then the low voltage condition exists.
-
If the PCM recognizes the high signal voltage, the PCM and the wiring are okay.
-
The 5-volt reference of the PCM supply is shared by the FTP, the TP, and the A/C position sensors. A short to ground at ANY of these sensors' 5-volt reference circuits OR an internally shorted sensor may cause this DTC to set. In order to determine the location of a shorted 5-volt reference supply, disconnect the sensors one at a time, beginning with the A/C sensor.
-
The sensor connectors must remain disconnected while the PCM connector remains connected for this step. The PCM terminals are spliced together inside the PCM. When inspecting the 5-volt reference circuit for a short to ground, all the 5-volt reference circuits must also be inspected..
Step | Action | Value(s) | Yes | No | ||||
|---|---|---|---|---|---|---|---|---|
1 | Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? | -- | ||||||
Does the scan tool display a TP sensor voltage less than the specified value? | 0.25 V | |||||||
3 | Depress the accelerator pedal to wide open throttle (WOT) while monitoring the TP angle on the scan tool. Does the TP angle increase smoothly through the specified range? | 0-100% | -- | |||||
4 | The DTC is intermittent. Are any additional DTCs set? | -- | Go to Diagnostic Aids | |||||
Does the scan tool display a TP sensor voltage that is more than the specified value? | 4.0 V | |||||||
6 |
Is the voltage more than the specified value? | 4.7 V | ||||||
7 |
Did you find a problem? | -- | ||||||
Inspect for a short to ground in the TP sensor 5-volt reference. Did you find a problem? | -- | |||||||
9 |
Did the voltage read more than the specified value after disconnecting one of the sensors? | 4.7 V | ||||||
10 |
Is the action complete? | 4.7 V | -- | |||||
11 |
Is the test lamp ON? | -- | ||||||
12 | Inspect for a faulty connection at the TP sensor. Did you find a problem? | -- | ||||||
13 | Inspect the TP sensor signal circuit for a short to ground. Did you find a problem? | -- | ||||||
14 | Inspect the TP sensor signal circuit for an open. Did you find a problem? | -- | ||||||
15 | Inspect for a short to ground in the 5-volt reference circuit to the FTP and A/C sensors. Did you find a problem? | -- | ||||||
16 |
Did you find a problem? | -- | ||||||
17 | Replace the TP sensor. Refer to Throttle Position Sensor Replacement . Is the action complete? | -- | -- | |||||
18 | Repair the circuit as necessary. Refer to Wiring Repairs or Connector Repairs in Wiring Systems. Is the action complete? | -- | -- | |||||
19 |
Important: Refer to Powertrain Control Module Replacement/Programming . Replace the PCM. Refer to Powertrain Control Module Replacement . Did you complete the replacement? | -- | -- | |||||
20 |
Does the scan tool indicate the diagnostic Passed? | -- | ||||||
21 | Does the scan tool display any additional undiagnosed DTCs? | -- | System OK |
