Rear Windshield washer reservoir

Washer System
The windshield washer and the rear window washer are activated by the internal wiper motor modules when they receive a ground from the multi-function switch between the washer inputs. Depending on the correct ground, the internal wiper motor modules activate either the windshield washer or the rear window washer relays (internal) by grounding the respective relay coil. When either relay is activated, it connects voltage to the washer pump while the deactivated relay provides ground to the washer pump. In this manner, voltage polarity is reversible to achieve directional change of the washer pump and washer fluid.

Washer Reservoir
Removal and Installation
WARNING:Windshield washer solution contains methanol, which is poisonous. Observe all cautions and warnings indicated on the label of the container. Failure to follow these instructions could result in personal injury.

CAUTION:When servicing the windshield washer pump, be careful not to damage the windshield washer pump seal.

CAUTION:Do not operate the windshield washer pump before filling the windshield washer reservoir. Failure to do so could result in premature pump failure.

Remove the air cleaner assembly. For additional information, refer to INTAKE AIR DISTRIBUTION & FILTERING .
Remove the RH front fender splash shield. For additional information, refer to FRONT END BODY PANELS .
Disconnect the windshield washer pump electrical connector.

Disconnect the windshield washer solvent level electrical connector.

NOTE:If necessary, drain the windshield washer reservoir after removal.

Disconnect the windshield washer reservoir hoses.
To install, tighten to 5 Nm (44 lb-in).
Remove the side bolt.
To install, tighten to 5 Nm (44 lb-in).

Remove the bolt.
To install, tighten to 5 Nm (44 lb-in).

Remove the windshield washer pump reservoir.
Transfer components as necessary.
To install, reverse the removal procedure.

They both use the same bottle, the internal wiper motor modules activate either the windshield washer or the rear window washer relays (internal) by grounding the respective relay coil. When either relay is activated, it connects voltage to the washer pump while the deactivated relay provides ground to the washer pump. In this manner, voltage polarity is reversible to achieve directional change of the washer pump and washer fluid.

I would check for clog in pipes and also check the rear relays, the pump must be working if the front are washing !! also check the fuses # 12 in underdash fuse box and # 30 in underhood fuse box