CUSTOMER CONCERN Cabin heat is inoperative and intermittent DTC 15470/P00B7-00 indicates insufficient engine-coolant flow. CAUSE The N82 coolant shut-off valve failed to respond despite 12-volt power at T2jk pin 1 and an ECM-commanded ground at pin 2, restricting coolant flow through the heater core. CORRECTION Remove and replace the failed N82 coolant shut-off valve, refill and bleed the cooling system, clear DTC 15470/P00B7-00, and verify heater-core flow and normal cabin h