Diagnostic Instructions

DTC Descriptor

DTC P2160: Vehicle Speed Sensor (VSS) 2 Circuit Low Voltage

DTC P2161: Vehicle Speed Sensor (VSS) 2 Circuit Intermittent

Diagnostic Fault Information

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
VSS Supply Voltage	P2160, P2161	P2160, P2161	P2160, P2161	P2161
VSS Signal	P2160, P2161	P2160, P2161	P2160, P2161	P2161

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 and torque converter clutch (TCC) scheduling, as well as transfer case range.

Conditions for Running the DTC

P2160

P2161

Conditions for Setting the DTC

P2160

The transfer case output shaft speed is 50 RPM or less for 4.5 seconds.

P2161

The transfer case output shaft speed drops 1,200 RPM or greater for at least 3.25 seconds.

Action Taken When the DTC Sets

Conditions for Clearing the DTC

DTCs P2160 and P2161 are Type B DTCs.

Diagnostic Aids

Reference Information

Schematic Reference

Connector End View Reference

Component Connector End Views

Description and Operation

Transfer Case Description and Operation

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

1. Raise and support the drive wheels.
2. Start and idle the engine.
3. Place the transmission in DRIVE.
4. Monitor VSS on the scan tool under engine data.
5. The VSS on the scan tool should be greater than 100 RPM.

Circuit/System Testing

1. Measure the resistance between the VSS high signal circuit and the VSS low signal circuit. The resistance should be between 1,420-2,140 ohms.

⇒	If the value is greater than 2,140 ohms, test the VSS high signal circuit and the VSS low signal circuit for an open.

⇒	If the value is less than 1,420 ohms, test the VSS high signal and the VSS low signal circuits for a shorted together condition.

2. Measure the resistance of the VSS high signal circuit to ground. The resistance should be greater than 10M ohms.

⇒	If the value is less than 10M ohms, repair the short to ground.

3. Measure the resistance between the VSS low signal circuit and ground. The resistance should be greater than 10M ohms.

⇒	If the value is less than 10M ohms, repair the short to ground.

4. Reconnect the ECM connector. Disconnect the VSS connector. Ignition ON, test the ISS high signal circuit for a short to voltage.

⇒	If all circuits/connections test normal, test or replace the VSS.

5. If all previous steps for circuit checking and VSS replacement have been made and all component testing has been performed and the condition persists replace the ECM.

Component Testing

1. Verify the VSS resistance is within the specified range.
2. Using a terminal test kit, connect the DMM between the VSS high signal and the VSS low signal circuits at the VSS connector. Raise and support the drive wheels. While rotating the drive wheels by hand ensure the AC voltage reading on the DMM is above 0.4 volts.

⇒	If the AC voltage is not above 0.4 volts, replace the VSS.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.