Technical Description of OBD-II Trouble Code
The range/performance of the control circuit for Pressure Control Solenoid E
What does that signify?
This is a generic diagnostic trouble code (DTC) for transmissions and applies to OBD-II vehicles with automatic transmissions. This includes vehicles from various manufacturers such as Ford, GMC, Chevrolet, Honda, BMW, Saturn, Land Rover, Acura, Nissan, Saturn, etc. Although it is a generic code, the specific repair steps may vary depending on the year, make, model, and powertrain configuration of the vehicle.
In most cases, automatic transmissions have at least three pressure control solenoids known as solenoid A, B, and C. Newer transmissions may have more gears and solenoids, including solenoids D, E, F, etc. The “E” solenoid control circuit is associated with various trouble codes, including P2727, P2728, P2729, and P2730. When the P2728 code is set, it means that the Powertrain Control Module (PCM) has detected a problem with the transmission pressure control solenoid “E” control circuit. The specific code set depends on the specific malfunction detected by the PCM.
An automatic transmission relies on bands and clutches that change gears by maintaining fluid pressure in the correct location at the right time. The purpose of the transmission pressure control solenoids is to adjust the fluid pressure for the automatic transmission to operate smoothly and shift properly. The PCM monitors the pressure within the solenoids and directs fluid to different hydraulic circuits to precisely change the transmission gear ratio as needed.
Code P2728 is set by the PCM when it detects that the control circuit for the “E” pressure control solenoid is outside the normal range for optimal performance.
Example of transmission solenoids:
What is the severity of this DTC?
Initially, the severity of this code is moderate, but if not corrected promptly, it can quickly escalate to a more severe level. If the transmission bangs into gear, it can cause permanent internal damage, making the problem a severe issue.
What are some of the symptoms of the code?
Symptoms of a P2728 trouble code may include:
What are some of the common causes of the code?
Causes for this P2728 transmission code may include:
What are some P2728 troubleshooting steps?
Prior to beginning the troubleshooting process for any malfunction, it is advisable to research the Technical Service Bulletins (TSB’s) for the specific vehicle based on the year, model, and transmission. This can save a significant amount of time by providing guidance in the right direction.
Inspections of Fluid & Wiring
The first step is to check the fluid level and examine the condition of the fluid for any contamination. Before changing the fluid, it is recommended to check the vehicle records to confirm when the filter and fluid were last changed.
Next, perform a detailed visual inspection to check the condition of the wiring for any obvious defects. Inspect the connectors and connections for security, corrosion, and damaged pins. This should include all wiring and connectors related to the transmission pressure control solenoids, transmission pump, and PCM. Depending on the specific configuration, the transmission pump may be driven electrically or mechanically.
Advanced Steps
The advanced steps are highly specific to each vehicle and require the appropriate advanced equipment for accurate performance. These procedures necessitate a digital multimeter and the specific technical references for the vehicle. It is essential to obtain the specific troubleshooting data for the vehicle before proceeding with the advanced steps. Voltage requirements and fluid pressure requirements may vary based on the specific model and transmission design.
Continuity Checks
Unless otherwise specified by the technical data, the normal readings for wiring and connections should be 0 ohms of resistance. Continuity checks should always be performed with the power removed from the circuit to avoid shorting the circuit and causing further damage. Resistance or lack of continuity indicates faulty wiring that is either open or shorted and must be repaired or replaced.
What are some common repairs for this code?
Possible misdiagnosis may include:
Hopefully, the information in this article will assist you in resolving the issue with your P2728 pressure control solenoid “E” control circuit diagnostic trouble code(s). This article is strictly for informational purposes, and the specific technical data and service bulletins for your vehicle should always take priority.
