Service park assist ?

[Ont240]

Service park assist ..HELP PLEASE

So here's my 07 Tahoe scenario.
About mid winter it flashed service on the DIC
Thought it was snow accumulation because that fixed it the first time so I thought.
Now with clear roads and clean sensor lenses:
Start engine put in reverse, red light at back, put in drive red light goes out, DIC shows service, Cancel button lower console is lit.
If I press the cancel button it flashes 4 times and stays lit all the time.

Are the proximity sensors prone to failure. Is it possable the cancel button is sticking internally and continuing to close a circuit?

 

[Ont240]

So here's my 07 Tahoe scenario.
About mid winter it flashed service on the DIC
Thought it was snow accumulation because that fixed it the first time so I thought.
Now with clear roads and clean sensor lenses:
Start engine put in reverse, red light at back, put in drive red light goes out, DIC shows service, Cancel button lower console is lit.
If I press the cancel button it flashes 4 times and stays lit all the time.

Are the proximity sensors prone to failure. Is it possable the cancel button is sticking internally and continuing to close a circuit?

bump

 

[Ont240]

so the dealer checked and said left rear sensor needs replacing.
Not at the price they want.
Ebay purchase

 

[Ont240]

Replaced the broken sensor.
Service park assist still shows.
Does the system need a reset?
how can this be accomplished?