Methods and systems for diagnosing performance of active cooling system in an electric vehicle

A method for performing a diagnostic operation on an active cooling system for cooling a rechargeable energy storage system (RESS) in an electric vehicle with a coolant, the method comprising:

• determining via a processor whether a first relative temperature (ΔT) of the coolant is less than a first calibrated delta value;
• when the first relative temperature of the coolant is less than the first calibrated delta value, determining whether a second relative temperature of the coolant is less than a second calibrated delta value, and when the second relative temperature of the coolant is less than the second calibrated delta value, recording a diagnostic pass;
• and
• when the second relative temperature of the coolant is not less than the second calibrated delta value, indicating that a more intrusive diagnostic is required.

A method for performing a diagnostic operation on an active cooling system for cooling a rechargeable energy storage system (RESS) in an electric vehicle with a coolant, the method comprising:

• calculating a relative coolant temperature (ΔT) by subtracting an ambient temperature plus a first calibrated value from a coolant temperature (TC−(TA+V1)) or by subtracting a RESS temperature plus a second calibrated value from the coolant temperature (TC−(TR+V2));
• determining via a processor whether the relative coolant temperature is less than a calibrated delta value;
• and
• recording a diagnostic pass when the relative coolant temperature is less than the calibrated delta value.