P1620

Diagnostic Chart:

Wiring Diagram:

The PCM monitors the 12 volt signal from the low coolant switch. When the switch opens indicating a low coolant condition, the PCM will not detect the 12 volt signal.

DTC PARAMETERS

DTC P1620 will set if:

^ The coolant switch opens (low signal) for 20 seconds with engine running.

CAUTION: THE LOW COOLANT CIRCUIT IS CONTINUOUSLY CHECKED WHEN THE ENGINE IS RUNNING.

DIAGNOSTIC AIDS

^ The low coolant switch is located in the coolant recovery tank and is a normally closed switch when the coolant bottle is at proper level.
^ Pressure check system for leaks.
^ Normally closed switch when coolant bottle is full.
^ The Low Coolant/HOT light will flash when coolant switch is open.