OBD-II Code P0758 is defined as a Shift Solenoid “B” Electrical issue. This code is triggered when the Transmission Control Module (TCM) detects that the shift solenoid responsible for shifting from 2nd gear to 3rd gear is not performing as expected.
What Does the P0758 Code Mean?
The P0758 code indicates that the Powertrain Control Module (PCM) is not detecting the specified RPM change that occurs during the transmission shift from 2nd to 3rd gear. This failure to shift can lead to significant performance issues and may impact the vehicle’s drivability.
What Causes the P0758 Code?
There are several common causes for the P0758 code, including:
- Defective Shift Solenoid
- Damaged or faulty wiring and connectors related to the shift solenoid
- Defective Valve Body
- Contaminated transmission fluid that restricts hydraulic passages
What Are the Symptoms of the P0758 Code?
When the P0758 code is present, drivers may experience the following symptoms:
- Illumination of the Check Engine Light
- Difficulty shifting from 2nd to 3rd gear
- A decrease in fuel economy
- In some cases, no noticeable symptoms may be present
- Potential performance issues, including misfire-like symptoms
How Serious Is the P0758 Code?
The P0758 code is considered urgent, indicating that immediate action is necessary. Ignoring this issue can lead to severe damage to the transmission or create unsafe driving conditions for the driver and passengers.
How to Diagnose the P0758 Code
Diagnosing the P0758 code involves the following steps:
- Record freeze frame information and replicate the conditions under which the code was set. Perform a test drive at speeds between 15-35 mph.
- Start from a complete stop and gently accelerate while monitoring the scan data for the PCM’s commands to the solenoid.
- If the PCM commands a shift and the vehicle does not shift properly, pinpoint tests such as voltage drops and continuity tests of the shift solenoid should be performed.
- Check the condition of the transmission fluid for clarity and any signs of contamination.
Common Repairs for the P0758 Code
Common repairs to address the P0758 code may include:
- Replacing the faulty Shift Solenoid
- Repairing or replacing damaged wiring or connectors
- Cleaning or replacing the Valve Body
- Changing the transmission fluid and ensuring proper levels
How Much Does It Cost to Fix the P0758 Code?
The cost of repairs associated with the P0758 code can vary significantly based on the underlying issue. On average, repairs may range from $150 to $600, depending on whether the shift solenoid, wiring, or transmission fluid needs attention.
Can I Fix the P0758 Code Myself?
While some aspects of diagnosing and repairing the P0758 code can be done by a knowledgeable DIY mechanic, it is recommended to have professional assistance for proper diagnosis and repair, especially if you’re unfamiliar with transmission systems. This ensures the underlying issues are accurately identified and corrected, saving time and potential additional costs.
