Like all parts on vehicles, shift solenoids tend to break down too. But will a bad shift solenoid throw a code? Many car owners are saying that their shift solenoid needed replacement, but they didn’t have a check engine light or a specific code associated with it.
This intrigued me. So, I cleared my afternoon and reach out to a couple of my good old friends who are experts in this area. This is what I found out:
Key Takeaway
What Are The Symptoms Of a Bad Shift Solenoid?
- A check engine light
- Gear shift delay
- Unable to shift gears
- Limp mode
Will a Bad Shift Solenoid Throw a Code?
Yes, a bad shift solenoid can throw a code and a check engine light. In fact, there are 37 trouble codes that a bad shift solenoid can throw. If the shift solenoid is not functioning properly, it can cause the vehicle to experience shifting problems or even get stuck in one gear. The ECU will usually detect this and throw a trouble code.
Here are the trouble codes that a bad shift solenoid will throw:
| Trouble Code | Meaning |
|---|---|
| P0750 – Shift Solenoid A Malfunction | Indicates that one of the solenoids (A) has failed |
| P0751 – Shift Solenoid A Performance or Stuck Off | Shift Solenoid A has performance issues |
| P0752 – Shift Solenoid A Stuck On | Shift Solenoid A is stuck in the ON position |
| P0753 – Shift Solenoid A Electrical | Shift Solenoid A has electrical issues |
| P0754 – Shift Solenoid A Intermittent | Shift Solenoid A has an intermittent electrical fault |
| P0755 – Shift Solenoid B Malfunction | Shift Solenoid B has malfunctioned |
| P0756 – Shift Solenoid B Performance or Stock Off | Shift Solenoid B has performance issues |
| P0757 – Shift Solenoid B Stuck On | Shift Solenoid B is stuck in the ON position |
| P0758 – Shift Solenoid B Electrical | Shift Solenoid B has electrical issues |
| P0759 – Shift Solenoid B Intermittent | Shift Solenoid B has an intermittent electrical fault |
| P075A – Shift Solenoid G Malfunction | Shift Solenoid G has malfunctioned |
| P075B – Shift Solenoid G Performance/Stuck Off | Shift Solenoid G has performance issues |
| P075C – Shift Solenoid G Stuck On | Shift Solenoid G is stuck in the ON position |
| P075D – Shift Solenoid G Electrical | Shift Solenoid G has electrical issues |
| P075E – Shift Solenoid G Intermittent | Shift Solenoid G has intermittent electrical issues |
| P075F – Transmission Fluid Level Too High | TFL sensor has detected that the transmission fluid is too high |
| P0760 – Shift Solenoid C Malfunction | Shift Solenoid C has malfunctioned |
| P0761 – Shift Solenoid C Performance or Stuck Off | Shift Solenoid C has performance issues |
| P0762 – Shift Solenoid C Stuck On | Shift Solenoid C stuck in the ON position |
| P0763 – Shift Solenoid C Electrical | Shift Solenoid C has electrical issues |
| P0764 Shift Solenoid C Intermittent | Shift Solenoid C has intermittent electrical issues |
| P0765 Shift Solenoid D Malfunction | Shift Solenoid D has malfunctioned |
| P0766 Shift Solenoid D Performance or Stuck Off | Shift Solenoid D has performance issues |
| P0767 Shift Solenoid D Stuck On | Shift Solenoid D stuck in the ON position |
| P0768 Shift Solenoid D Electrical | Shift Solenoid D has electrical issues |
| P0769 Shift Solenoid D Intermittent | Shift Solenoid D has intermittent electrical issues |
| P076A Shift Solenoid H Malfunction | Shift Solenoid H has malfunctioned |
| P076B Shift Solenoid H Performance/Stuck Off | Shift Solenoid H has performance issues |
| P076C Shift Solenoid H Stuck On | Shift Solenoid H stuck in the ON position |
| P076D Shift Solenoid H Electrical | Shift Solenoid H has electrical issues |
| P076E Shift Solenoid H Intermittent | Shift Solenoid H has intermittent electrical issues |
| P076F Gear 7 Incorrect Ratio | Transmission not shifting to seventh gear due to incorrect fluid pressure |
| P0770 Shift Solenoid E Malfunction | Shift Solenoid E has malfunctioned |
| P0771 Shift Solenoid E Performance or Stuck Off | Shift Solenoid E has performance issues |
| P0772 Shift Solenoid E Stuck On | Shift Solenoid E stuck in the ON position |
| P0773 Shift Solenoid E Electrical | Shift Solenoid E has electrical issues |
| P0774 Shift Solenoid E Intermittent | Shift Solenoid E has intermittent electrical issues |
What Is The Purpose of The Shift Solenoid
The purpose of the shift solenoid is to control the shifting of the gears in a vehicle. When the solenoid is activated, it allows fluid to flow into the transmission, which then activates the gears. This helps to ensure that the vehicle shifts smoothly and efficiently.
The shift solenoid is an on-and-off electrical valve that lets transmission fluid pass to actuate the gearshift. While most transmissions have two or three solenoids, the number of maximum shift solenoids on transmission is four. Most of the transmissions only employ two or three solenoids 80% of the time.
All modern transmissions use pressure control solenoids to control the position of the boost valve. The solenoid is controlled by a control module. The control module uses an on-off technique called a duty cycle to control the position of the pintle which ultimately controls the flow of fluid through the solenoid. Pressure control solenoids are often called PC solenoids, line pressure solenoids, or EPC solenoids which stands for electronic pressure control line.
Transmission solenoids are located inside the transmission. A transmission solenoid’s job is to direct the hydraulic fluid into the valve body to engage the correct gear. Common signs of bad transmission solenoids are erratic shifting, shift slippage, and a transmission that will not shift at all.
Basically, when you have a bad transmission solenoid, the transmission solenoid is unable to send the hydraulic pressure into the transmission valve body to select the proper gear.
What Are The Symptoms Of a Bad Shift Solenoid?
The purpose of the shift solenoids is to open up and allow fluid to pass through the valve body. The channels inside the valve body lead to the automatic transmission, the pressurized clutch packs, and bands to activate specific gear changes. These solenoids get activated by the transmission control module depending on the vehicle’s speed sensors and others.
The location of the shift solenoids will typically be underneath the transmission oil pan around the valve body.
1. Check engine light
The first symptom of a bad shift solenoid is an engine light. A bad shift solenoid might also throw an OBD code as well. If the transmission control module senses anything wrong with the solenoids, it’s going to turn on the check engine light to warn the driver and set a diagnostic code. Some cars might show a check light specifically designed for transmission problems.
There are some trouble codes related to the solenoids. While scanning a vehicle with a bad shift solenoid, codes like P0750 (Shift Solenoid A), P0755 (Shift Solenoid B), P0760 (Shift Solenoid C), P0765 (Shift Solenoid D), or P0770 (Shift Solenoid E) might show.
2. Gear shift delay
The second symptom you might be experiencing if your vehicle has a bad shift solenoid is a gear shift delay. The reason why this happens is that the shift solenoids can get dirty and clogged through time. This usually occurs due to dirty transmission fluid. Since the solenoid is dirty, it’s going to reduce the fluid pressure from passing through efficiently, therefore, delaying the time for the gear change.
3. Unable to shift gears
The third symptom you might be experiencing if your vehicle has one or multiple shift solenoids is your transmission not being able to change gears. If the shift solenoid is stuck closed or not opening, the fluid will never be able to pressurize through the valve body to activate the specific clutch packs and bands inside the transmission to change gears. If this happens, you won’t be able to put your car in drive or reverse.
4. Limp mode
Limp mode is a safety feature that protects your car. Since the shift solenoid is responsible for changing gears in your car, it puts your safety at risk. That’s why limp mode is activated. You’ll feel your car is a lot slower because your RPMs and speed will be limited. A vehicle that enters limp mode due to bad shift solenoids is usually stuck in second or third gear.
What Will a Bad Shift Solenoid Do?
A bad shift solenoid will restrict and significantly decrease the flow of transmission fluid and will result in a check engine light, gear shift delay, unable to shift gears at all, or a limp mode. Basically, transmission fluids travel through the solenoids under pressure and into the valve body to activate a certain gear. When clogged, the shift solenoids are unable to provide a constant flow of pressurized transmission fluid. Without the fluid, you will have a hard time shifting or your vehicle won’t be able to shift gears at all.
