DTC 04

Solenoid Schematic:

Diagnostic Trouble Code (DTC) 4, Grounded Antilock Pressure Valve Reset Switch:

CIRCUIT DESCRIPTION
A Diagnostic Trouble Code (DTC) 4 relates to a grounded condition in the Antilock Pressure Valve (APV) reset switch. The reset switch grounds pin C of the Electronic Brake Control Module (EBCM) 4-way connector when there is a great enough difference between inlet and outlet pressure in the antilock pressure valve.

An example of this is during a pressure decrease operation. With a grounded reset switch, the EBCM has no way of determining if pressure changes are occurring in the antilock pressure valve. The reset switch is constantly signaling that pressure decrease has occurred.

TEST DESCRIPTION
- Clear the DTCs in the EBCM memory.
- Check the voltage signal to the reset switch to see if the EBCM is operational.

DIAGNOSTIC AIDS

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.