CUSTOMER CONCERN The coolant-temperature gauge reads full hot and the combination meter stores DTC B1503. The exhaust temperature switch has already been replaced, but the code immediately returns and both switch wires measure 0 volts with the switch disconnected. CAUSE Rodent damage chewed through the exhaust-temperature-switch wiring beneath the vehicle near the floor area. CORRECTION Repair the damaged exhaust-temperature-switch wiring, clear DTC B1503, and verify the temp