What does it mean?
This is a generic diagnostic trouble code (DTC) and generally applies to OBD-II equipped vehicles with an automatic transmission.
This can include, but is not limited to, vehicles from Ford, Mercury, Lincoln, Jaguar, Chevrolet, Toyota, Nissan, Allison/Duramax, Dodge, Jeep, Honda, Acura, etc. Although generic, the exact repair steps may vary by year, make, model, and powertrain configuration.
When the OBD-II fault code P0776 is set, the Powertrain Control Module (PCM) has detected a problem with the transmission pressure control solenoid “B”. Most automatic transmissions have at least three solenoids, which are solenoids A, B, and C. Fault codes related to solenoid “B” are codes P0775, P0776, P0777, P0778, and P0779. The code set is based on the specific malfunction that alerts the PCM and illuminates the Check Engine light.
Transmission pressure control solenoids are designed to control fluid pressure for the proper operation of an automatic transmission. The PCM receives an electronic signal based on the pressure inside the solenoids. An automatic transmission is controlled by bands and clutches that shift gears by having fluid pressure in the right place at the right time. Based on signals from associated devices monitoring vehicle speed, the PCM commands the pressure solenoids to direct fluid at the appropriate pressure to various hydraulic circuits that change the transmission ratio at the right moment.
The P0776 code is set by the PCM when the pressure control solenoid “B” is not functioning correctly or is stuck in the “Off” position.
How severe is this DTC?
The severity of this code normally starts as moderate, but it can quickly escalate to a more severe level if not corrected in a timely manner.
What are some of the symptoms of the code?
Symptoms of a P0776 fault code may include:
- The vehicle enters limp mode
- Transmission slips when shifting gears
- Transmission overheating
- Transmission shifts harshly
- Reduced fuel economy
Symptoms
Potential misfires, Check Engine light on
What are some common causes of the code?
Causes of this P0776 transmission code may include:
- Faulty pressure control solenoid
- Dirty or contaminated fluid
- Dirty or clogged transmission filter
- Faulty transmission pump
- Faulty transmission valve body
- Restricted hydraulic passages
- Corroded or damaged connector
- Faulty or damaged wiring
- Faulty PCM
What are the troubleshooting steps for P0776?
Before starting the troubleshooting process for any malfunction, you should research Technical Service Bulletins (TSBs) for the specific vehicle by year, model, and transmission. In some circumstances, this can save you a lot of time in the long run by pointing you in the right direction. You should also check the vehicle’s records to verify the last time the filter and fluid were changed, if possible.
Fluid and Wiring Inspections
The first step is to check the fluid level and examine the condition of the fluid for contamination. Before changing the fluid, you should check the vehicle’s records to verify the last time the filter and fluid were changed.
A detailed visual inspection to check the condition of the wiring for obvious defects is next. Check connectors and connections for security, corrosion, and damaged pins. This should include all wiring and connectors for the transmission pressure control solenoids, transmission pump, and PCM. Depending on the configuration, the transmission pump may be electric or mechanical.
Advanced Steps
Advanced steps always become very vehicle-specific and require appropriate advanced equipment to perform accurately. These procedures require a digital multimeter and vehicle-specific technical references. You should obtain troubleshooting guidelines specific to your vehicle before proceeding with advanced steps. Voltage requirements can be very specific to the particular vehicle model. Fluid pressure requirements will also vary depending on the transmission’s design and configuration.
Continuity Checks
Unless otherwise indicated in the technical data, normal readings for wiring and connections should be 0 ohms of resistance. Continuity checks should always be performed with the power disconnected from the circuit to avoid short-circuiting and causing further damage. Resistance or lack of continuity indicates faulty wiring that is open or shorted and must be repaired or replaced.
What are the common repairs for this code?
- Replacing fluid and filter
- Replacing the faulty pressure control solenoid
- Repairing or replacing a faulty transmission pump
- Repairing or replacing the faulty transmission valve body
- Flushing the transmission to clean passages
- Cleaning corrosion from connectors
- Repairing or replacing wiring
- Reprogramming or replacing the PCM
Possible misdiagnosis may include:
- Engine misfire issue
- Transmission pump problem
- Internal transmission problem
- Transmission issue
I hope the information in this article has helped guide you in the right direction to correct the issue with your pressure control solenoid fault code. This article is strictly informational, and the technical data and service bulletins specific to your vehicle should always take priority.