DTC 06

Speed Signal Schematic:

Diagnostic Trouble Code (DTC) 6, Erratic Speed Signal:

CIRCUIT DESCRIPTION
A Diagnostic Trouble Code (DTC) 6 is a soft fault. If the speed signal line to the Electronic Brake Control Module (EBCM) drops out and returns often, this DTC is set in memory. The BRAKE lamp will illuminate when the DTC is set and turn off with the next ignition cycle.

Do not replace the EBCM to repair this DTC. An erratic speed signal relates to a malfunction in either the Vehicle Speed Sensor (VSS) , VSS buffer, or speed signal circuit. It can be set by a poor connection in the speed signal line.

TEST DESCRIPTION
Check if all systems are receiving an erratic speed signal or if it is just the Rear Wheel Antil Lock (RWAL) system.
- Check the VSS output using the Tech 1.
- Check the resistance of the VSS.
- Check for an open condition in CKT 822.
- Check for excessive resistance in CKT 696.

DIAGNOSTIC AIDS
Do not replace the EBCM for this DTC. An EBCM malfunction will not cause this DTC to set.

If the voltage readings are low or varying, the battery, charging system, or intermittent connections could be the cause. Check these areas before replacing any components.

This DTC is a soft fault and can be set with a 2WD transmission on ice wheel spins

If the BRAKE lamp is not on, do not ground Data Line Connector (DLC) terminals H to A. Doing so will set a false DTC 9.

CAUTION: Do not pierce the electrical connectors, wires, seals, or insulation during testing. Doing so will break the seal and lead to corrosion and failure of the wiring and terminals.