P0980 OBD-II Trouble Code: Shift Solenoid C Control Circuit High

P0980 code definition

The P0980 diagnostic trouble code is an indication that there is an issue with the shift solenoid C control circuit.

What the P0980 code means

Shift solenoids and speed sensors are used in an automatic transmission to change gears. The transmission control module (TCM) collects information from the speed sensors and sends a signal to the shift solenoids indicating whether an upshift or downshift is necessary. The transmission control module (TCM) constantly monitors the shift solenoids and speed sensors and will perform resistance checks to ensure they are working properly. If the resistance check performed by the transmission control module (TCM) is not within the predetermined specification the faulty shift solenoid will be disabled, the P0980 diagnostic trouble code will be stored, and the check engine light will come on indicating there is a problem.

What causes the P0980 code?

• Faulty shift solenoid
• Dirty transmission fluid
• Low levels of transmission fluid
• Shift solenoid wiring that is frayed, broken, or shorted
• Shift solenoid connectors that are damaged or corroded
• Transmission itself is faulty
• Faulty transmission control module (TCM)

What are the symptoms of the P0980 code?

• Check Engine Light is on
• Car is hard to shift
  
• High RPMs when shifting
• Increase of fuel consumption
• Poor engine acceleration
• Driveability issues

How does a mechanic diagnose the P0980 code?

• Diagnostic trouble codes should be diagnosed in the order that they appear in the powertrain control module (PCM).
• Use an OBD-II scanner to collect all trouble codes that have been stored by the powertrain control module (PCM) as well as freeze frame data.
• Check the transmission fluid. If fluid levels are low, refill the transmission fluid. If the fluid is dirty, replace the transmission fluid.
• Clear all diagnostic trouble codes from powertrain control module (PCM) and operate the vehicle to see if the P0980 diagnostic trouble code comes back.
• If the P0980 trouble code does come back, inspect the shift solenoid wiring and connectors for frays, breaks, corrosion and damage.
• Repair or replace damaged shift solenoid wiring and/or connectors as necessary.
• Clear all diagnostic trouble codes from powertrain control module (PCM) and operate the vehicle to see if the P0980 diagnostic trouble code comes back.
• If the P0980 trouble code does come back, inspect the transmission control module (TCM) connectors for damage and corrosion.
• If the vehicle is equipped with external shift solenoids inspect those connectors for damage and corrosion as well.
• Repair and replace damaged connectors as necessary.
• Clear all diagnostic trouble codes from powertrain control module (PCM) and operate the vehicle to see if the P0980 diagnostic trouble code comes back.
• If the P0980 trouble code does come back, use a digital volt ohm meter to test the shift solenoid circuits for proper operation.
• If the results of the test do not meet the manufacturer’s predetermined specifications, the shift solenoid will need to be replaced.
• Clear all diagnostic trouble codes from powertrain control module (PCM) and operate the vehicle to see if the P0980 diagnostic trouble code comes back.
• If the P0980 trouble code comes back, the transmission control module (TCM) may be faulty.

Common mistakes when diagnosing the P0980 code

• Broken or chafed wiring is overlooked and not repaired
• Dirty transmission fluid is not considered a possible cause of the P0980 trouble code
• Other failed transmission parts are not diagnosed and repaired before replacing the faulty shift solenoid

How serious is the P0980 code?

A diagnostic trouble code is normally considered serious when it causes driveability issues or a change in performance. Severe driveability problems will exist while this code is stored in the powertrain control module (PCM). It may also be impossible to operate the vehicle at all. For this reason, the P0980 diagnostic trouble code is considered extremely serious and should be diagnosed and repaired as soon as possible.

What repairs can fix the P0980 code?

• Faulty shift solenoid replacement

• Dirty transmission fluid replacement

• Refill low transmission fluid levels

• Repair or replace shift solenoid wiring that is frayed, broken, or shorted

• Repair or replace shift solenoid connectors that are damaged or corroded

• Replace or rebuild faulty transmission

• Replace faulty transmission control module (TCM)

Additional comments for consideration regarding the P0980 code

If the shift solenoid is located on the outside of the transmission, this tends to be an easy fix. Internal shift solenoids are more difficult to fix and sometimes require removing the transmission from the vehicle. At times, the best fix for the P0980 diagnostic trouble code is to replace the transmission.

Need help with a P0980 code?

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