P0947 OBD-II Trouble Code: Hydraulic Pump Relay Circuit Low

P0947 code definition

The P0947 code is a generic powertrain code related to the transmission, including pressure faults and sensor failures. In this case, the transmission control module has detected a low voltage signal coming from the hydraulic pump relay circuit.

What the P0947 code means

A vehicle utilizes the pump to generate hydraulic pressure. Channels direct the transmission fluid in an automatic transmission to the valve body. The shift solenoid valves and pressure control solenoid valves are both located in the valve body. The transmission control module manages and activates electronically controlled valves, which are utilized for gear shifting. In particular, the shift solenoid manages the clutch, brakes, and bands in the transmission while the pressure control solenoid valve (one or more) manages the hydraulic pressure inside the vehicle’s transmission.

A code P0947 will be stored when the transmission control valve receives a voltage signal lower than manufacturer-specific allowed variations from one of the valves.

What causes the P0947 code?

Several problems may cause a P0947 code including:

• Low transmission fluid
• Dirty transmission fluid
• Damaged or defective wiring or related electrical connector
• Damaged or defective hydraulic pump relay
• Damaged or defective transmission control module
• Damaged or defective ECM

What are the symptoms of the P0947 code?

Symptoms of a P0947 code may include:

• Check engine or warning light may illuminate
• Vehicle may shift roughly
• Vehicle may not shift at all
• May experience transmission slippage

How does a mechanic diagnose the P0947 code?

A mechanic may use several methods to diagnose a P0947 trouble code, including:

• Utilize an OBD-II scanner to check for a stored P0947 trouble code
• Check transmission fluid levels
• Check transmission fluid quality
• Check transmission pan for possible debris, including clutch debris, which could be the sign of a larger transmission-related problem
• Visually inspect the wiring and electrical components related to the hydraulic pump relay circuit for possible damage
• Check, in specific, the harness from the transmission control module to the transmission for any signs of damage
• Check resistance across terminals
• Repeat resistance test at transmission connector if resistance is not at normal levels

Common mistakes when diagnosing the P0947 code

With any transmission-related fault code, it is recommended to check transmission fluid levels and quality, test drive the vehicle, and rescan to see if the code reappears prior to performing more complicated diagnosis and repairs.

How serious is the P0947 code?

Because a vehicle’s safe driving operation most likely will be impacted due to faults that store a P0947 code, this code is considered a potentially serious code. When this code appears, it is recommended to immediately take your vehicle to your local service center or mechanic for repair and diagnosis.

What repairs can fix the P0947 code?

Several repairs can fix a P0947 trouble 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 damaged or defective harness from transmission control module to transmission

• Replace damaged or defective hydraulic pump

• Replace damaged or defective transmission control module

• Replace damaged or defective ECM

• Clear all codes, test-drive the vehicle, and rescan to see if any codes reappear

Additional comments related to a P0947 code

The pressure control solenoid valve is often located inside the transmission, which can be a difficult repair. It is recommended to utilize a professional for diagnosis and repair for a P0947 code.

Need help with a P0947 code?

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