Pressure control solenoids are little plunger’s that the ECU can turn on and off by sending an electrical charge through a coil of wire that is wrapped around the plunger mechanism. This allows the computer to modulate the amount of hydraulic pressure inside the transmission, so it can execute shifts. If the ECU detects a low voltage signal along the pressure control solenoid C circuit, it will save a P0970 DTC.
How Serious is the Code?
A P0970 diagnostic trouble code is very serious, because it means the ECU is not going to be able to control the amount of hydraulic pressure inside the transmission. This will lead to a number of transmission problems that include unusually harsh gear changes, slipping, transmission overheating and engine stalling.
Symptoms of a P0970 include:
- Transmission slips
- Unusually firm gear changes
- Transmission overheats
- Engine will stall when you slow down or come to a stop
- Engine misfire-like symptoms
- Limp mode
- Dirty transmission filter and fluid
- Damaged/frayed wiring
- Corroded or broken connectors
- Pressure control solenoid failure
- Transmission pump failure
- Valve body failure
- TCM/ECU problems
How to Diagnose the Code?
Diagnosing a P0970 OBDII trouble code, should start with examining the simple issues first. These are the level and condition of the transmission fluid, and checking the wiring harness along the transmission for signs of damage wires or broken/corroded connectors. If nothing is found to be wrong, then an in-depth diagnosis of the transmission pressure control solenoid(s), valve body, transmission pump and possibly the ECU and TCM will be needed.
What Repairs Will Fix P0970?
- Change the transmission fluid and filter
- Repair or replace damaged wiring and connectors
- Install new pressure control solenoid(s)
- Repair or replace transmission pump
- Repair or replace the valve body
- Reprogram or replace the ECU or TCM
- P0968 – Pressure Control Solenoid “C” Control Circuit/Open
- P0969 – Pressure Control Solenoid “C” Control Circuit Range/Performance
- P0971 – Pressure Control Solenoid “C” Control Circuit High