Definition of Code P0947
Code P0947 is a generic powertrain code related to the transmission, including pressure faults and sensor failures. In this case, the transmission control module detected a low voltage signal from the hydraulic pump relay circuit.
What Does Code P0947 Mean?
A vehicle uses the pump to generate hydraulic pressure. The channels direct transmission fluid in an automatic transmission to the valve body. Both the shift solenoids and the pressure control solenoids are located in the valve body. The transmission control module manages and activates the electronically controlled valves, which are used for shifting. Specifically, the shift solenoid controls the transmission’s clutch, brakes, and bands, while the pressure control solenoid (one or more) manages the hydraulic pressure inside the vehicle’s transmission.
A code P0947 will be recorded when the transmission control valve receives a voltage signal lower than the manufacturer-specific allowable variations from one of the valves.
What Causes Code P0947?
Several issues can cause a code P0947, including:
- Low transmission fluid
- Dirty transmission fluid
- Damaged or faulty wiring or associated electrical connector
- Damaged or faulty hydraulic pump relay
- Damaged or faulty transmission control module
- Damaged or faulty ECM
What Are the Symptoms of Code P0947?
Symptoms of a code P0947 may include:
- Check engine or warning light may illuminate
- Vehicle may shift roughly
- Vehicle may not move at all
- May exhibit transmission slipping
How Does a Mechanic Diagnose Code P0947?
A mechanic may use several methods to diagnose a P0947 fault code, including:
- Using an OBD-II scanner to check for a stored P0947 fault code
- Checking transmission fluid levels
- Checking transmission fluid quality
- Checking the transmission pan for any debris, including clutch debris, which could indicate a larger transmission-related issue
- Visually inspecting wiring and electrical components related to the hydraulic pump relay circuit for possible damage
- Specifically checking the transmission control module harness to the transmission for any signs of damage
- Checking resistance between terminals
- Repeating the resistance test at the transmission connector if resistance is not at normal levels
Common Mistakes When Diagnosing Code P0947
With any transmission-related error code, it is recommended to check transmission fluid levels and quality, test the vehicle, and reanalyze to see if the code reappears before performing more complicated diagnostics and repairs.
How Severe Is Code P0947?
Since safely operating a vehicle will most likely be affected due to faults that store a P0947 code, this code is considered potentially severe. When this code appears, it is recommended to bring your vehicle to your local service center or a mechanic immediately for repair and diagnosis.
What Repairs Can Fix Code P0947?
Several repairs can correct a P0947 fault code and include:
- Fill transmission fluid to manufacturer-recommended levels
- Change or perform a transmission fluid flush, if necessary
- Repair or replace damaged, open, shorted, or corroded wiring and electrical components related to the hydraulic pump relay circuit
- Replace the damaged or faulty transmission control module harness to the transmission
- Replace the damaged or faulty hydraulic pump
- Replace the damaged or faulty transmission control module
- Replace the damaged or faulty ECM
- Clear all codes, test the vehicle, and reanalyze to see if any codes reappear