P0958 Fault Code

ASM Mode Circuit High

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

The P0958 fault code refers to the ASM (Automated Shift Management) Mode Circuit High issue in vehicles. This code is related to the transmission's electronic controls and indicates that there is a potential problem with the signal sent from the ASM system. Proper communication between the transmission control module (TCM) and other vehicle systems is crucial for smooth operation.

What are the symptoms of the P0958 code?

Symptoms associated with the P0958 code may include:

• Harsh shifting or slipping of gears
• Delayed engagement when shifting into gear
• Warning lights illuminated on the dashboard (such as the check engine light)
• Transmission not responding as expected during operation
• Unusual noises coming from the transmission

What causes the P0958 code?

Common causes of the P0958 code include:

• Faulty or damaged wiring in the ASM circuit
• A malfunctioning ASM control module
• Poor connection or corrosion at electrical connectors
• Issues with the transmission control module (TCM)
• Low transmission fluid levels or quality
• Internal transmission failure or wear

How to fix P0958?

To fix the P0958 fault code, follow these steps:

• Inspect the wiring and connectors for any visible damage or corrosion; repair or replace as necessary.
• Test the ASM control module to ensure it is functioning properly; replace if faulty.
• Check fluid levels and condition; top off or replace transmission fluid as needed.
• Clear the fault code from the vehicle's computer and test drive the vehicle to see if the issue persists.
• If needed, perform a more in-depth diagnosis of the transmission system for internal failures.