P1790 Code - Fault Immediately After Shift
Quick Answer
This Diagnostic Trouble Code (DTC) is set if the engine is running and the vehicle speed is more than 10 mph in Drive, and the Transmission Control Module (TCM) detects a Speed Ratio Code within 1.3 seconds after a shift event occurs. Common causes include Transmission has an internal mechanical problem. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
- What it means
- P1790 indicates Fault Immediately After Shift.
- Common causes
- Common causes include Transmission has an internal mechanical problem.
- Severity
- High - diagnose this code as soon as possible.
- Can I drive?
- Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
Code P1790 Description
What are the Possible Causes of the DTC P1790?
- Transmission has an internal mechanical problem
How to Fix the DTC P1790?
Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P1790 code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.
Need more information about the P1790 code?
Need more information on how to fix the P1790 code? Get Access to Factory Service Manuals
Need Help with the Code?
Get the P1790 code diagnosed by a professional: Find a repair shop in your area
Information for Specific Makes
- P1790 Acura — Throttle Position Sensor Circuit Malfunction
- P1790 Buick — Transmission Control Module Checksum
- P1790 Cadillac — Transmission Control Module Checksum
- P1790 Chevrolet — Transmission Control Module Checksum
- P1790 Chrysler — Fault Immediately After Shift
- P1790 Dodge — Fault Immediately After Shift
- P1790 GMC — Transmission Control Module Checksum
- P1790 Honda — Throttle Position Sensor Circuit Malfunction
- P1790 Isuzu — Lock-Up Clutch Not Engaging
- P1790 Jeep — Fault Immediately After Shift
- P1790 Lexus — ST Solenoid Valve Circuit Malfunction
- P1790 Mazda — Throttle Position Sensor Malfunction
- P1790 RAM — Fault Immediately After Shift
- P1790 Toyota — ST Solenoid Valve Circuit Malfunction
Frequently Asked Questions about P1790 Code
1. What are the common symptoms of OBDII code P1790 (Fault Immediately After Shift)?
- Common symptoms include harsh shifting, delayed shifting, transmission slipping, and the transmission going into limp mode.
2. What are the possible causes of OBDII code P1790 (Fault Immediately After Shift)?
- Possible causes include low transmission fluid, a faulty transmission solenoid, a malfunctioning transmission valve body, or wiring issues.
3. How can I diagnose OBDII code P1790 (Fault Immediately After Shift)?
- Diagnosis typically involves using a scan tool to retrieve the code, checking the transmission fluid level and condition, inspecting the wiring and connectors, and testing the transmission solenoids.
4. Can driving with OBDII code P1790 (Fault Immediately After Shift) cause further damage?
- Continuing to drive with this code may lead to further damage to the transmission components, resulting in more costly repairs.
5. What are some repair tips for fixing OBDII code P1790 (Fault Immediately After Shift)?
- Repair tips may include checking and topping up the transmission fluid, replacing the transmission solenoid, inspecting and repairing any damaged wiring, and performing a transmission fluid flush.
6. Is it safe to continue driving my vehicle with OBDII code P1790 (Fault Immediately After Shift)?
- It is not recommended to drive the vehicle with this code present, as it can lead to transmission issues and potential safety hazards on the road.
7. How much does it typically cost to repair OBDII code P1790 (Fault Immediately After Shift)?
- The cost of repairs for this code can vary depending on the specific cause of the issue, but it may range from a few hundred dollars to over a thousand dollars.
8. Can OBDII code P1790 (Fault Immediately After Shift) be a DIY fix?
- Some basic repairs for this code, such as checking and filling the transmission fluid, can be done as a DIY fix. However, more complex issues may require professional help.
9. How urgent is it to address OBDII code P1790 (Fault Immediately After Shift)?
- It is important to address this code promptly to prevent further damage to the transmission and ensure the vehicle's safe operation.
10. What should I do if OBDII code P1790 (Fault Immediately After Shift) keeps coming back after repairs?
- If the code keeps reappearing after repairs, it may indicate an underlying issue that was not properly addressed initially. It is recommended to have a professional mechanic further diagnose the problem.
Discuss the causes and fixes for P1790 OBDII Code
Code P1790 comments
No comments found for this page.
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.
