The P0803: 1-4 Upshift (Skip Shift) Solenoid Control Circuit Malfunction refers to an issue in the control circuit responsible for the 1-4 upshift (skip shift) solenoid, which is designed to manage gear shifts between the first and fourth gears. This issue may be caused by a faulty solenoid, wiring or connector issues, or a malfunctioning transmission control module (TCM).
P0803 – Quick Overview
| Code | Information |
|---|---|
| Meaning | P0803: 1-4 Upshift (Skip Shift) Solenoid Control Circuit Malfunction |
| Is it serious? | Yes, this can affect gear shifting, leading to poor drivability or skipping gears improperly. |
| Possible causes | – Faulty 1-4 upshift (skip shift) solenoid – Wiring or connector issues – Faulty transmission control module (TCM) |
| How to diagnose? | – Test 1-4 upshift solenoid – Inspect wiring and connectors – Replace faulty solenoid or TCM if necessary |
P0803 Meaning
The P0803 code indicates that there is a malfunction in the control circuit for the 1-4 upshift (skip shift) solenoid. This solenoid is designed to skip certain gears under specific conditions to improve fuel efficiency and optimize shifting. A failure in this circuit can lead to improper shifting or a lack of control over the skip shift function.
Step-by-step diagnostic guide
| Action | Description | Tools Needed |
|---|---|---|
| Check for Other Codes | Use an OBD-II scanner to check for any additional transmission-related codes that may give further insight into the issue. | OBD-II Scanner |
| Test 1-4 Upshift Solenoid | Use a multimeter or diagnostic tool to test the solenoid for continuity and correct operation. Verify that the solenoid is functioning within manufacturer specifications. | Multimeter, Diagnostic Scanner |
| Inspect Wiring and Connectors | Visually inspect the wiring and connectors leading to the 1-4 upshift solenoid for damage, corrosion, or loose connections that may cause the control circuit malfunction. | Flashlight, Multimeter, Safety Gloves |
| Check Transmission Fluid | Ensure the transmission fluid level is correct and the fluid is clean, as low or contaminated fluid can affect solenoid performance. | Transmission Fluid Tester, Dipstick |
| Test Transmission Control Module (TCM) | If no issues are found in the solenoid, wiring, or connectors, test the TCM for faults or communication errors that may be causing the malfunction. | Diagnostic Scanner, TCM Testing Tools |
| Replace Faulty Solenoid or TCM | If the solenoid or TCM is found to be faulty, replace it according to manufacturer specifications. | Replacement Parts, Wrenches, Screwdrivers |
| Clear the Code and Test Drive | After replacing or repairing the solenoid or TCM, clear the code using an OBD-II scanner and test drive the vehicle to ensure the issue is resolved. | OBD-II Scanner |
| Recheck for Codes | After the test drive, rescan the vehicle to ensure the P0803 code has not returned. | OBD-II Scanner |
OBD-II scanner Buyer’s Guide
- Scanner features explained
- Different types of scanners
- Scanners for coding/odometer/ECU/checks
- Best picks + discount codes
Hi, I am Juraj “Yuri” Lukacko. I got frustrated by unhelpful and scammy mechanics, so I decided to learn everything about car diagnostics myself. I test dozens of new car diagnostic tools every month along with learning new strategies to fix and customize cars. About Juraj Lukacko (Yuri)