K 2500 Yukon 4WD V8-6.0L VIN U (2000)
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Diagnostic Chart (Part 2 Of 2)
Schematic
CIRCUIT DESCRIPTION
The engine coolant level switch is located in the radiator surge tank. The engine coolant level switch is a float type switch. The Powertrain Control
Module (PCM) supplies a voltage to the engine coolant level switch. The engine coolant level switch is a normally open switch. When the coolant
level is within an acceptable range the engine coolant level switch closes. The switch opens when the engine coolant level drops below a
predetermined amount. When the PCM detects a high signal voltage, switch open, from the engine coolant level switch the PCM sends a Class 2
message to the Instrument Panel Cluster (IPC). The IPC displays the LOW COOLANT message.