B0001

DTC B0001

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.



DTC Descriptor
DTC B0001
- Vehicle Speed Information Circuit Range/Performance




Diagnostic Fault Information






Circuit/System Description

The engine control module (ECM) creates the vehicle speed output signal by pulsing the circuit to ground at a rate of 4 KPPM. The VSS input is pulled high to B+ in the radio. The ECM monitors the voltage at the vehicle speed signal circuit to determine when the voltage is out of the normal operating range.


Conditions for Running the DTC

* Vehicle speed must exceed 4 km/h (2.5 mph) after receiving a global positioning system (GPS) signal.
* Engine speed is more than 400 RPM.
* Battery voltage must be between 9-16 volts.



Conditions for Setting the DTC

The navigation radio compares the vehicle speed signal from the ECM to the GPS location signal every second. If the GPS signal indicates that the vehicle has traveled 4 km (2.5 mph) but no vehicle speed signal was received, the radio sets the DTC.


Action Taken When the DTC Sets

The navigation radio may exhibit the following conditions when a fault is present:

* The vehicle icon may jump to different positions on the map screen.
* The vehicle icon, current position marker may not move on the map screen while the vehicle is being driven.
* The route guidance accuracy may be degraded.



Conditions for Clearing the DTC

* The condition responsible for setting the DTC no longer exists.
* A history DTC will clear once 50 consecutive malfunction-free ignition cycles have occurred.



Reference Information
Schematic Reference

Radio/Navigation System Schematics (Radio/Navigation System Schematics)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

Navigation System Description and Operation (Navigation System Description and Operation)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

Control Module References (Programming and Relearning) for scan tool information


Circuit/System Testing

Important: The drive wheels of the vehicle must be raised and the transmission must be placed in drive or first gear. Refer to Lifting and Jacking the Vehicle (Service and Repair) .



1. Ignition OFF, disconnect the X1 harness connector at the radio.
2. Engine ON, drive wheels raised, place the vehicle in drive or first gear. With a scan tool, verify the speedometer value matches the scan tool vehicle speed parameter in the ECM engine data list.

• If the speedometer matches the scan tool vehicle speed parameter, test the vehicle speed signal circuit terminal F2 for a short to voltage, short to ground, or an open/high resistance. If the circuit tests normal, replace the radio.


• If the speedometer does not match the scan tool vehicle speed parameter, refer to Speedometer and/or Odometer Inaccurate or Inoperative (Speedometer and/or Odometer Inaccurate or Inoperative) .




Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.


Control Module References (Programming and Relearning) for Radio replacement, setup, and programming