P0500

DTC P0500

CIRCUIT DESCRIPTION
The vehicle speed sensor (VSS) 2 is used by the engine control module (ECM) and speedometer, which generates a speed signal from the transmission output shaft rotational speed. The VSS 2 has the following circuits.
- 12 volts feed circuit
- VSS 2 signal circuit
- VSS 2 low reference circuit

The VSS 2 uses a hall effect element. It interacts with the magnetic field created by the rotating magnet and outputs a square wave pulse signal. The ECM calculates the vehicle speed by the VSS 2. If the ECM detects a difference of VSS 1 signal input from the transmission control module (TCM) higher than the VSS 2 signal inputted to the ECM, this DTC will set (Automatic Transmission).

If the ECM detects the VSS 2 signal inputted to the ECM lower than a predetermined speed during the calculated engine condition, this DTC will set (Manual Transmission).

Condition for Running the DTC
Automatic Transmission
- DTCs P0643, P0700, U0073 and U0101 are not set.
- The ignition switch ON time is longer than 3 seconds.

Manual Transmission
- DTCs P0643, P0700, U0073 and U0101 are not set.
- The ignition switch ON time is longer than 2 seconds.
- The engine speed is higher than 1100 RPM.
- The engine coolant temperature (ECT) is more than 68 °F (20 °C).
- The fuel injection quantity is more than a calculated value.

Condition for Setting the DTC
Automatic Transmission
- The ECM detects that the VSS 1 signal from the TCM is 15 MPH higher than the VSS 2 signal inputted to the ECM for 10 seconds.

Manual Transmission
- The ECM detects that the VSS 2 signal inputted to the ECM is lower than a predetermined speed for 10 seconds.

Action Taken When the DTC Sets
- The ECM illuminates the malfunction indicator lamp (MIL) on the second consecutive driving cycle when the diagnostic runs and fails.
- The ECM records the operating conditions at the time the diagnostic fails. The ECM stores this information in the Freeze Frame/Failure Records on the second consecutive driving cycle when the diagnostic runs and fails.
- The ECM inhibits the cruise control.
- The ECM inhibits the PTO control.

Condition for Clearing the MIL/DTC
- The ECM turns OFF the MIL after 3 consecutive driving cycles when the diagnostic runs and does not fail. (12,000 lbs GVW)
- The ECM turns OFF the MIL when the diagnostic runs and does not fail. (Except 12,000 lbs GVW)
- A current DTC, Last Test Failed, clears when the diagnostic runs and passes after the key is cycled.
- A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic after the ECM turns OFF the MIL.
- Clear the MIL and the DTC with a scan tool.

Diagnostic Aids
If an intermittent condition is suspected, the following may cause an intermittent:
- Poor connections
- Misrouted harness
- Rubbed through wire insulation
- Broken wire inside the insulation

Check for the following conditions:
- Poor connection at the ECM: Inspect harness connectors for backed-out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal to wire connection.
- Damaged harness: Inspect the wiring harness for damage. If the harness appears to be OK, observe the "Vehicle Speed Sensor" display on the scan tool while driving the vehicle. A change in the display to 0 MPH (0 km/h) indicates a fault is occurring.

DTC P0500
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls Connector End Views or Engine Control Module (ECM) Connector End Views

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