P0977 GMC - Shift Solenoid 'B' Open Or Short To Power
P0977 GMC Possible Causes
- Low transmission fluid level
- Dirty transmission fluid
- Faulty shift solenoid 'B' valve
- Shift solenoid 'B' valve harness or connectors
- Shift solenoid 'B' valve circuit is open or shorted
How is the P0977 GMC code repair?Start by checking the "Possible Causes" listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector's pins.
What is the cost to diagnose the P0977 GMC code
Labor: 1.0The cost to diagnose the P0977 GMC code is 1.0 hour of labor. The auto repair labor rates vary widely across the country, and even within the same city. Most auto repairs shops charge between $75 and $150 per hour.
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- Engine Light ON (or Service Engine Soon Warning Light)
P0977 GMC MeaningThe Powertrain Control Module (PCM) controls the ground signal for shift solenoid B to control the solenoid ON or OFF, according to transaxle and vehicle operation. When the solenoid is OFF, filtered line pressure to the solenoid is exhausted. When energized (ON), the exhaust port is blocked, stopping the exhaust of line pressure through the solenoid, and directing it into the solenoid B passage. Solenoid B fluid pressure is then fed to the 4-3 manual downshift valve and the 3-2 manual downshift valve.
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