P0887 Buick Transmission Control Module (TCM) Power Relay Control Circuit High

P0888 Buick Transmission Relay Always Off

Possible causes
– Transmission Control Relay harness is open or shorted
– Transmission Control Relay circuit poor electrical connection
– Faulty Transmission Control Relay
– Faulty Transmission Solenoid/Pressure Switch Assembly
Symptoms
– Engine Light ON (or Service Engine Soon Warning Light)
P0888 Buick Description

The Transmission Control Module (TCM) has detected less than 3 volts at the Transmission Control Relay output circuit

Buick Vehicle:Buick Regal – ?Buick Riviera – ?Buick LaCrosse – ?David Dunbar Buick – Buick Century – Buick LaCrosse – Buick LeSabre – Buick Lucerne – Buick Park Avenue – Buick Regal – Buick Verano – Buick Enclave – Buick Encore – Buick Rainier – Buick Rendezvous – Buick Terraza – Buick Riviera