2010 Cadillac CTS Sedan AWD V6-3.0L Page 1462

2010 Cadillac CTS Sedan AWD V6-3.0L Page 1462

2. Measure for 1,300-1,500 ohms at 25掳C (77掳F) between the VSS high signal circuit terminal 66 and the VSS low signal circuit terminal 67.

瀚慖f the value is greater than 1,500 ohms test the VSS high signal circuit and the VSS low signal circuit for an open/high resistance. If the

circuits/connections test normal, replace the vehicle speed sensor.

瀚慖f the value is less than 1,300 ohms test the VSS high signal and the VSS low signal circuits for a shorted together condition. If the

circuits/connections test normal, replace the vehicle speed sensor.

3. Measure for more than 10 ohms of resistance between the VSS high signal circuit terminal 66 and ground.

瀚慖f the value is less than the specified range, repair the short to ground.

4. Measure for more than 10 ohms of resistance between the VSS low signal circuit terminal 67 and ground.

瀚慖f the value is less than the specified range, repair the short to ground.

5. Reconnect the ECM connector. Disconnect the VSS connector.

6. Ignition ON, test the VSS high signal circuit terminal B for a short to voltage.

瀚慖f all circuits/connections test normal, test or replace the VSS.

Repair Instructions

Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the repair.

* Vehicle Speed Sensor Replacement (See: Powertrain Management/Computers and Control Systems/Sensors and Switches - Computers and

Control Systems/Vehicle Speed Sensor/Service and Repair/Tremec 6-Speed - Manual Transmission)

* Control Module References (See: Testing and Inspection/Programming and Relearning) for ECM replacement, setup and programming

P0503

DTC P0502 or P0503

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System

Check - Vehicle) prior to using this diagnostic procedure.

* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an

overview of the diagnostic approach.

* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure

Instructions) provides an overview of each diagnostic category.

DTC Descriptor

DTC P0502

- Vehicle Speed Sensor (VSS) Circuit Low Voltage

DTC P0503

- Vehicle Speed Sensor (VSS) Circuit Intermittent

Diagnostic Fault Information

Circuit/System Description

The vehicle speed information is provided to the engine control module (ECM) by the vehicle speed sensor (VSS). The VSS is a permanent magnet

generator that is mounted to the transmission and produces a pulsing voltage. The AC voltage amplitude and frequency increases with vehicle

speed. The ECM converts the pulsing voltage into km/h (mph). The ECM supplies the VSS signal to the following components:

* The instrument panel for speedometer and odometer operation

* The cruise control module

Conditions for Running the DTC