B0001

DTC B0001

DTC Descriptor

DTC B0001
- Vehicle Speed Information Circuit Range/Performance

Circuit/System Description

The radio receives a vehicle speed signal from the electronic brake control module (EBCM) in order to correlate actual vehicle speed to the movement of the vehicle calculated by the navigation system and reported serial data

Conditions for Running the DTC

* The navigation radio must detect a power mode transition to ON.
* The radio does not set this DTC if B1327 or B1328 is current.
* The vehicle must drive for 4 km (2.5 mph) after receiving a global positioning system (GPS) signal.

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 uses the GPS signal when the vehicle speed signal from the ECM is unavailable.

The following symptoms may happen if the vehicle speed signal from the ECM is unavailable:

* 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

* A current DTC clears when the navigation radio detects the vehicle speed signal from the ECM for more than one second.
* A history DTC clears after 50 ignition cycles without a vehicle speed signal failure.

Circuit/System Testing

1. Test drive the vehicle. Verify the vehicle speedometer is operating properly.

• If the speedometer is inaccurate or inoperative, go to Speedometer and/or Odometer Inaccurate or Inoperative. Speedometer and/or Odometer Inaccurate or Inoperative

2. Test or repair open circuit on the vehicle speed sensor circuit to the radio.

• If all circuits test normal, replace the ECM.

Repair Instructions

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

for EBCM replacement, setup, and programming

Refer to Programming and Relearning. Programming and Relearning