2010 Cadillac CTS Sedan AWD V6-3.6L Page 1466
2. Measure the resistance between each terminal of the EVAP vent solenoid valve and the EVAP vent solenoid valve housing. The DMM
should display OL.
瀚慖f not the specified value, replace the EVAP vent solenoid valve.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
* Evaporative Emission Canister Vent Solenoid Valve Replacement (See: Powertrain Management/Emission Control Systems/Evaporative
Emissions System/Evaporative Emission Control Canister/Canister Vent Valve/Service and Repair)
* Control Module References (See: Testing and Inspection/Programming and Relearning) for ECM replacement, setup, and programming
P0501
DTC P0501 or P0502
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 Descriptors
DTC P0501
- Vehicle Speed Sensor (VSS) Performance
DTC P0502
- Vehicle Speed Sensor (VSS) Circuit Low Voltage
Diagnostic Fault Information
Typical Scan Tool Information
Circuit/System Description
Vehicle speed information is provided to the engine control module (ECM) by the vehicle speed sensor (VSS). The VSS consists of a hall-effect
sensor mounted to the transmission case which interfaces with a rotor pressed onto the transmission output shaft. The hall-effect sensor contains a
permanent magnet and a semiconductor plate to which ignition voltage is applied. As the output shaft spins, the rotor directs the field of the
permanent magnet either toward or away from the plate. The VSS produces a frequency signal that is proportional to vehicle speed. The ECM
converts the VSS signal to vehicle speed, displayed on the scan tool in kilometers per hour or miles per hour. The ECM also uses the VSS signal to
generate the 4,000 pulses per mile vehicle speed signal used by the instrument cluster.
Conditions for Running the DTC
* The engine speed is greater than 1800 RPM for 3 seconds.
* The engine coolant temperature (ECT) is greater than 40掳C (104掳F).
