P2798 Fault Code

Auxiliary Transmission Fluid Pump Control Circuit Low

• What does that mean?
• Symptoms
• Causes
• Solutions

The P2798 fault code indicates an issue with the auxiliary transmission fluid pump control circuit, specifically that the circuit is experiencing low voltage or current. This component is crucial for maintaining transmission pressure, which helps in the smooth operation of automatic transmissions. When this code is triggered, it can lead to various transmission-related issues.

What are the symptoms of the P2798 code?

Vehicles experiencing a P2798 code may exhibit certain symptoms such as:

• Slipping or delayed shifting between gears
• Unusual noises from the transmission while in operation
• Increased engine RPM without a corresponding increase in vehicle speed
• Warning lights on the dashboard, sometimes including the check engine light
• Overheating transmission, resulting in reduced performance.

What causes the P2798 code?

Several factors can lead to a P2798 fault code, including:

• A defective auxiliary transmission fluid pump
• A faulty wiring harness or connector that affects the pump's operation
• Low transmission fluid levels, which can impact the pump's ability to function correctly
• Short circuits or open circuits within the control circuit, leading to erratic pump behavior
• Issues with the transmission control module (TCM) that may improperly regulate pump activity.

How to fix P2798?

To resolve a P2798 fault code, the following steps are recommended:

• Inspect and test the auxiliary transmission fluid pump for proper operation, replacing it if defective.
• Check the wiring and connections related to the auxiliary pump for signs of damage, corrosion, or loose connections, and repair or replace as necessary.
• Ensure that the transmission fluid level is at the proper level and that the fluid itself is clean and free of contaminants; consider changing the fluid if needed.
• Use a diagnostic scanner to check for other related fault codes that could provide additional insight into the issue, and address them accordingly.
• If no mechanical issues are found, consider reprogramming or replacing the transmission control module if it is suspected to be malfunctioning.