P0803 – OBD-II DTC

OBD-II DTC P0803 – Shift/Timing Solenoid High

DTC P0803 meaning

DTC P0803 refers to a diagnostic trouble code indicating a problem with the shift or timing solenoid in the transmission system. This code specifically points to a high voltage condition detected in the solenoid circuit, which can affect the transmission’s ability to shift gears properly. The shift solenoid is responsible for controlling the flow of transmission fluid, and any malfunction can lead to performance issues.

DTC P0803 symptoms

Common symptoms associated with DTC P0803 may include:

• Delayed or harsh shifting between gears
• Transmission slipping or failing to engage
• Check Engine Light illuminated
• Unusual noises from the transmission
• Reduced fuel efficiency

DTC P0803 causes

Several factors can lead to the occurrence of DTC P0803, including:

• Faulty shift solenoid
• Wiring issues, such as shorts or open circuits
• Corroded or damaged connectors
• Low transmission fluid levels or contamination
• Faulty transmission control module (TCM)

DTC P0803 seriousness

The seriousness of DTC P0803 can vary, but it is generally considered a moderate to high priority issue. If left unaddressed, it can lead to significant transmission problems, including complete failure to shift gears. This can result in unsafe driving conditions and potentially costly repairs. It is advisable to diagnose and repair the issue promptly.

How to diagnose DTC P0803

To diagnose DTC P0803, follow these steps:

1. Use an OBD-II scanner to confirm the presence of the P0803 code.
2. Inspect the transmission fluid level and condition.
3. Check the wiring and connectors related to the shift solenoid for damage or corrosion.
4. Test the shift solenoid for proper operation using a multimeter.
5. Examine the transmission control module for faults.
6. Clear the code and perform a road test to see if the code returns.

How to fix DTC P0803 step-by-step instructions

To fix DTC P0803, follow these steps:

1. Check and top off the transmission fluid if low.
2. Inspect and repair any damaged wiring or connectors.
3. Replace the faulty shift solenoid if testing indicates it is not functioning correctly.
4. Reprogram or replace the transmission control module if necessary.
5. Clear the DTC using an OBD-II scanner.
6. Test drive the vehicle to ensure the issue is resolved and the code does not return.

How to erase DTC P0803

To erase DTC P0803, follow these steps:

1. Connect an OBD-II scanner to the vehicle’s diagnostic port.
2. Turn on the ignition without starting the engine.
3. Access the scanner’s menu and select the option to clear or erase trouble codes.
4. Confirm the action and wait for the scanner to complete the process.
5. Disconnect the scanner and start the vehicle to check if the code reappears.

Recommended tools for OBD-II diagnostics

Explore our expert picks: The Best OBD2 Scanners for 2025

Easy-to-use Multimeter for reliable diagnostics: AstroAI Auto-ranging Multimeter

Some of the links on this page may be affiliate links, which means we may earn a small commission if you make a purchase. This helps us keep our DTC database up to date and provide valuable content for free. We only recommend products that we have tested and believe to be the best in their class.