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For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2000 🢒 Catera 🢒 Engine 🢒 Engine Controls - 3.0L (L81) 🢒 DTC P0500 Vehicle Speed Sensor (VSS) Circuit

Refer to Antilock Brake System Schematics

CAN Interface and VSS Signal


Object Number: 596309 Size: FS
.

Circuit Description

The left rear wheel speed sensor provides a signal to the electronic brake and traction control module (EBTCM). In addition to wheel speed information, the signal from the left rear wheel speed sensor provides the only input for vehicle speed information. The EBTCM sends out a vehicle speed signal based on the information from this sensor. The vehicle speed signal is sent to the theft deterrent module and to all other modules requiring vehicle speed information. The vehicle speed signal to the theft deterrent module is then sent to the engine control module on the same circuit used to communicate the theft deterrent information.

Conditions for Running the DTC
    • The decel fuel cut-off is enabled.
    • The engine speed is between 1800-2200 RPM.
    • The engine coolant temperature (ECT) is more than 65°C (149°F).

Conditions for Setting the DTC

The vehicle speed signal (VSS) is less than 20 km/h (12 mph) for longer than 1 second.

Action Taken When the DTC Sets

The ECM turns ON the malfunction indicator lamp (MIL) and records the operating conditions in the Freeze Frame on the second consecutive drive trip that the diagnostic runs and fails.

Conditions for Clearing the MIL/DTC
    • The ECM turns OFF the MIL after three consecutive drive trips that the diagnostic runs and passes.
    • A History DTC clears after forty consecutive warm-up cycles in which no failures are reported by this diagnostic or any other emission related diagnostic.
    • The scan tool clears the MIL/DTC.

Diagnostic Aids

Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems for intermittent concerns.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. If a DTC P1502 is set, the vehicle will not start or may start and stall. DTC P1502 indicates the condition causing the DTC P0500 is located in the circuit between the theft deterrent module and the ECM.

    2.

  2. This step is to determine if the EBTCM is capable of producing a vehicle speed signal.

    3.

  3. This step is to determine if the vehicle speed signal is available at the theft deterrent module.

    4.

  4. This step is to determine if the theft deterrent module is causing the loss of the vehicle speed signal.

    5.

  5. This step is to isolate each of the modules connected to the vehicle speed signal circuit to determine if any of the modules are causing the loss of the signal. This step also prepares the vehicle for the next two steps by having all of the components on the signal circuit disconnected in order to test for a short to ground or a short to voltage.

Step

Action

Values

Yes

No

1

Did you perform the Powertrain On-Board Diagnostic (OBD) System check?

--

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

2

With a scan tool, review the ECM DTC information.

Is a DTC P1502 set?

--

Go to DTC P1502 Theft Deterrent Fuel Enable Signal Not Received

Go to Step 3

3

  1. Turn OFF the ignition.
  2. Raise the drive wheels.
  3. Turn ON the ignition, with the engine OFF.
  4. Shift the gear selector to neutral.
  5. Rotate the left rear wheel by hand while observing the speedometer.

Does the speedometer indicate a vehicle speed above the specified value?

0.0 km/h (0.0 mph)

Go to Step 6

Go to Step 4

4
  1. Perform Diagnostic System Check - ABS in Antilock Brake System.
  2. Repair any DTCs or concerns that would prevent the EBTCM from providing a vehicle speed signal.

Did you find and repair a concern with the EBTCM System?

--

Go to Step 17

Go to Step 5

5

  1. Test for an open vehicle speed signal circuit between the EBTCM and splice 222.
  2. Repair the circuit as necessary. Refer to Wiring Repairs in Wiring Systems.

Did you find and repair an open circuit?

--

Go to Step 17

Go to Step 7

6

  1. Turn OFF the ignition.
  2. Disconnect the theft deterrent module.
  3. Use a DMM set to the AC, Hz, 40 Hz scale in order to measure the frequency between the vehicle speed signal circuit at the theft deterrent module and ground.
  4. Turn ON the ignition, with the engine OFF.
  5. Shift the gear selector to neutral.
  6. Rotate the left rear wheel by hand while observing the DMM.

Does the DMM indicate a frequency above the specified value?

10 Hz

Go to Step 12

Go to Step 13

7

  1. Turn OFF the ignition.
  2. Disconnect the theft deterrent module.
  3. Turn ON the ignition, with the engine OFF.
  4. Shift the gear selector to neutral.
  5. Rotate the left rear wheel by hand while observing the speedometer.

Does the speedometer indicate a vehicle speed above the specified value?

0.0 km/h (0.0 mph)

Go to Step 16

Go to Step 8

8

  1. Turn OFF the ignition.

    2. Important: Do not disconnect the EBTCM connector for this test. Turn OFF the ignition before disconnecting each module.

  2. Disconnect each module connected to the vehicle speed signal circuit one at a time and perform the following steps:
    3. 2.1. Use a DMM set to the AC, Hz, 40 Hz scale in order to measure the frequency between the vehicle speed signal circuit at the theft deterrent module and ground.
    2.2. Turn ON the ignition, with the engine OFF.
    2.3. Rotate the left rear wheel by hand while observing the DMM.
  3. Repeat the above steps with each of the modules connected to the vehicle speed signal circuit.

Does the DMM indicate a frequency above the specified value after disconnecting any of the modules?

10 Hz

Go to Step 14

Go to Step 9

9
  1. Turn OFF the ignition.
  2. Disconnect the EBTCM connector.
  3. Test the vehicle speed signal circuit for a short to ground. Refer to Testing for Short to Ground in Wiring Systems.

Did you find and repair a short to ground?

--

Go to Step 17

Go to Step 10

10
  1. Turn ON the ignition.
  2. Test the vehicle speed signal circuit for a short to voltage. Refer to Testing for a Short to Voltage in Wiring Systems.

Did you find and repair a short to voltage?

--

Go to Step 17

Go to Step 11

11

Test for poor connections/terminal tension at the EBTCM harness connector. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Did you find and correct a problem?

--

Go to Step 17

Go to Step 15

12

Test for poor connections/terminal tension at the theft deterrent module harness connector. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Did you find and correct a problem?

--

Go to Step 17

Go to Step 16

13

Repair the open vehicle speed signal circuit between splice 222 and the theft deterrent module. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 17

--

14

Replace the most recently disconnected module. Refer to the appropriate repair instructions for module replacement.

Did you complete the replacement?

--

Go to Step 17

--

15

Replace the EBTCM. Refer to Electronic Brake and Traction Control Module Replacement in Antilock Brake System.

Is the replacement complete?

--

Go to Step 17

--

16

Replace the theft deterrent module. Refer to Theft Deterrent Module Replacement in Theft Deterrent.

Is the replacement complete?

--

Go to Step 17

--

17
  1. Use the scan tool in order to clear the DTCs.
  2. Start the engine.
  3. Allow the engine to idle until the engine reaches normal operating temperature.
  4. Select DTC and the Specific DTC function.
  5. Enter the DTC number that was set.
  6. Operate the vehicle within the Conditions for Running this DTC until the scan tool indicates that the diagnostic Ran.

Does the scan tool indicate that the diagnostic Passed?

--

Go to Step 18

Go to Step 2

18

Does the scan tool display any additional undiagnosed DTCs?

--

Go to the applicable DTC table

System OK