GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2007 🢒 Lucerne 🢒 DTC 🢒 DTC P2162

Circuit Description

The vehicle speed signal circuit is an input to the throttle actuator control (TAC) module from the powertrain control module (PCM). The PCM provides a constant voltage signal on the vehicle speed signal circuit. The PCM creates the vehicle speed signal by internally pulsing the vehicle speed signal to ground. The TAC module uses the vehicle speed signal from the PCM, in order to determine the vehicle speed. The TAC module then sends a universal asynchronous receiver transmitter (UART) serial data message to the PCM indicating the vehicle speed that the TAC module has detected.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P2162 Vehicle Speed Sensor (VSS) Circuit 1-2 Correlation

Conditions for Running the DTC
    • The vehicle is in Drive or Reverse.
    • The vehicle speed is greater than 8 km/h (5 mph).
    • There are no VSS DTCs present in the PCM.
    • The ignition voltage is between 9-16 volts.

Conditions for Setting the DTC
    • The PCM sends a 8 km/h (5 mph) signal on the vehicle speed signal circuit to the TAC module. The TAC module sends a UART serial data message to the PCM indicating that the vehicle speed is 0 km/h (0 mph).
    • The condition must be present for greater than 4 seconds.

Action Taken When the DTC Sets
    • The Cruise Control System is disabled.
    • The PCM stores a DTC P2162 in memory.
    • The PCM records the operating conditions at the time the DTC sets. The PCM displays the failure information in the Failure Records on the scan tool.

Conditions for Clearing the DTC
    • The history DTC clears after 40 malfunction free warm-up cycles.
    • The DTC becomes history when the conditions for setting the DTC are no longer present.
    • The PCM receives the clear code command from the scan tool.

Diagnostic Aids

For intermittent diagnosis, refer to Testing for Intermittent Conditions and Poor Connections .

Step

Action

Yes

No

Schematic Reference: Cruise Control Schematics

Connector End View Reference: Master Electrical Component List

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2
  1. Turn OFF the ignition.
  2. Install a scan tool.
  3. Raise the vehicle drive wheels. Refer to Lifting and Jacking the Vehicle .
  4. Start the engine.
  5. Place the transmission into drive.
  6. With a scan tool, observe the Vehicle Speed Sensor parameter in the Body and Accessories, Cruise Control data list.

Does the Vehicle Speed Sensor parameter indicate any vehicle speed?

Go to Step 4

Go to Step 3

3

Is DTC P0502 or P0503 current in the powertrain control module (PCM)?

Go to DTC P0502 or DTC P0503

Go to Step 5

4

Test the vehicle speed signal circuit for the following:

    • A short to ground
    • An open
    • A high resistance

Refer to Circuit Testing and to Wiring Repairs .

Did you find and correct the condition?

Go to Step 9

Go to Step 6

5

Inspect for poor connections at the harness connector of the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 9

Go to Step 7

6

Inspect for poor connections at the harness connector of the throttle actuator control (TAC) module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 9

Go to Step 8

7

Replace the PCM. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 9

--

8

Replace the TAC module. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 9

--

9
  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running the DTC.

Does the DTC reset?

Go to Step 2

System OK