Transmission Fluid Pressure Switch 5 Circuit Low
Table of contents
P0989 BUICK Possible Causes
- Faulty Control Solenoid Valve Assembly
- Control Solenoid Valve Assembly harness is open or shorted
- Control Solenoid Valve Assembly circuit poor electrical connection
How do I fix code P0989 BUICK?
Check 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.
Cost of diagnosing the P0989 BUICK code
The cost of diagnosing the P0989 BUICK code is 1.0 hour of labor. The auto repair labor rates vary by location, your vehicle’s make and model, and even your engine type. Most auto repairs shops charge between $75 and $150 per hour.
Possible Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
P0989 BUICK Description
The Transmission Fluid Pressure (TFP) Switch 5 is part of the control solenoid (w/body and Transmission Control Module (TCM)) valve assembly and is not serviced separately. The TCM supplies 12 volts to the TFP switch 5 on the TFP switch 5 signal circuit; the TFP switch 5 has an internal case ground. TFP switch 5 is normally closed, Low. When oil pressure is present at the TFP switch 5, the switch is open, high. The normally low clutch pressure control (PC) solenoid 4 controls the transmission fluid to the 1-2-3-4 clutch. The TCM monitors the normally closed TFP switch 5 signal circuit to determine the 1-2-3-4 clutch status. The Diagnostic Trouble Code (DTC) will set TCM detects that the TFP Switch 5 signal voltage remains low, 0 volts when the low and reverse clutch or the 4-5-6 clutch is commanded ON for 5.5 seconds or greater.