What is P0784 fault code and what does it mean? What is the description of 4-5 shiftting malfunction? How can you fix the P0784 fault code What are the causes and symptoms of the P0784 error code?
What is the P0784 fault code? What does it all mean?
For vehicles with electronic controlled automatic transmissions, the shift solenoid 4-5 is responsible for activating hydraulic circuits to activate clutches or bands. The powertrain control module (PCM), and transmission control module, respectively, control the shift solenoids. Fault code P0784 can be set when the PCM detects a problem with the 4-5 Shift function.
The PCM calculates desired gear ratios using engine speed and engine load. The engine’s gear ratios improve performance and reduce fuel consumption. The fault code P0784 is set when the PCM determines that the desired and current gear ratios are not in sync. Sometimes multiple faults could occur before the checkengine light turns on.
The image below shows where the shift solenoids are found in an automatic transmission.
What is the P0784 Fault Code?
Below are some reasons to set fault code P0784:
- – Defective 4-5 shift solenoid
- – Blockage of transmission fluid passage lines
- – Internal transmission problems
- – Low transmission oil
- – Filtering and oil contamination in transmission oil
- – Switch solenoid wiring harness can be opened or closed
- – A poor electrical connection in shift solenoid circuit
- – Connectors and cables that are damaged
- – Defective transmission pump
- – Hydraulic control unit failure
- – Rarely: Defective PCM/TCM
What are the symptoms of P0784 Malfunction Code?
These symptoms may be present in vehicles with code P0784.
- – Illumination for the check engine light
- – Difficulty shifting gears
- Vehicle is not shifting between 4th and 5th gear
- – Gearbox slip
- Overheating the gearbox can lead to burning odors
- – An increase of fuel consumption
- – Irregularity of idle speed
- – Vehicle stalling when it is idle
- – Vehicle hesitation when acceleration is applied
- – Setting other fault codes in relation to shift solenoids
- – Vehicle enters failsafe mode and allows only one gear
How do I fix the P0784 fault code?
The following repairs may be able to resolve the P0784 fault code:
- – Replacing a faulty solenoid for 4-5 shifts
- Flushing of transmission fluid lines
- – Top up your transmission fluid
- – Change dirty transmission fluid or filter
- Repair of damaged or open cables
- – Reparing the bad electrical connection in the shift solenoid circuit
- – Replacing damaged cables or connectors
- Repairing a damaged transmission pump
- – Replacing a defective hydraulic control unit
- – In rare cases, replacement of TCM or PCM
How Serious Is the P0784 Fault Coding?
The P0784 code, if not addressed, can lead to shifting problems, increased fuel consumption, and transmission overheating. The transmission could be damaged if it is left exposed to low fluid too long.
