test normal, test the VSS for proper operation.
3. Using the J 35616-64B L-BU probes, test for greater than 1 M ohm between the following circuits and a good ground.
* VSS high signal circuit, ECM harness X1 pin 71.
* VSS low signal circuit, ECM harness X1 pin 72.
锟斤拷If the resistance is below the specified value, test the affected circuit for being shorted to ground. If all circuits and connections test
normal, test the VSS for proper operation.
4. Reprogram the ECM. If the DTC continues to set, replace the ECM.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
* Ensure that the VSS is 500 RPM or greater for 3 seconds and does not change more than 500 RPM or greater for 3 seconds.
* Vehicle Speed Sensor Replacement (See: Powertrain Management/Computers and Control Systems/Sensors and Switches - Computers and
Control Systems/Vehicle Speed Sensor/Service and Repair/MP 3010-NP0 - Transfer Case)
* Control Module References (See: Testing and Inspection/Programming and Relearning) for ECM replacement, setup, and programming
MP 3010-NP0 - Transfer Case
DTC P2160 or P2161
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 P2160
- Vehicle Speed Sensor (VSS) 2 Circuit Low Voltage
DTC P2161
- Vehicle Speed Sensor (VSS) 2 Circuit Intermittent
Diagnostic Fault Information
Circuit/System Description
The vehicle speed sensor (VSS) provides vehicle speed information to the engine control module (ECM). The VSS is a permanent magnet
generator. The sensor is mounted in the transfer case facing the rear internal gear which is splined to the output shaft assembly. As the output shaft
and internal gear rotate, the toothed rotor of the internal gear produces AC voltage as the rotor teeth pass through the magnetic field of the sensor.
The AC voltage level and the number of pulses increase as the speed of the vehicle increases. The ECM converts the voltage to vehicle speed. The
ECM uses the output shaft speed signal to determine shift timing, as well as transfer case range.
Conditions for Running the DTC
P2160
* No input speed sensor (ISS) DTCs P0716 or P0717.
* The throttle position is greater than 5 percent and less than 99 percent.
* The transmission is not in Reverse Inhibit state.
* The transmission is not in PARK or NEUTRAL.
* The transmission is not performing garage shifting.
* No engine torque, throttle position, and turbine speed DTCs.
* The engine torque is greater than 60 Nm (44 lb ft) and less than 8192 Nm (6042 lb ft).
* The input speed is greater than 1000 RPM and less than 7500 RPM.
