AutoCodes – Toyota – P1790 2002 Toyota Echo

P1790 2002 Toyota Echo Code - ST Solenoid Valve Circuit Malfunction

Quick Answer

Shift solenoid valve ST is switched ON-OFF by a signal from ECM so that let in or out timing of 2nd brake is adjusted by operating orifice control valve. Common causes include Open or short in shift solenoid valve ST circuit, Shift solenoid valve ST. 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 2002 Toyota Echo indicates ST Solenoid Valve Circuit Malfunction.
Common causes: Common causes include Open or short in shift solenoid valve ST circuit, Shift solenoid valve ST.
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.

Save to My Repairs My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

Code Popularity 2,752

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Sep 19, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

Code P1790 2002 Toyota Echo Description

Shift solenoid valve ST is switched ON-OFF by a signal from ECM so that let in or out timing of 2nd brake is adjusted by operating orifice control valve. Therefore, shift solenoid valve ST operates when letting in or out reverse clutch. f it is broken, the shift shock becomes big.

OBDII Code P1790 2002 Toyota Echo - ST Solenoid Valve Circuit Malfunction - AutoCodes.com — P1790 2002 Toyota Echo Code - ST Solenoid Valve Circuit Malfunction

What does this mean?

What are the Possible Causes of the DTC P1790 2002 Toyota Echo?

Open or short in shift solenoid valve ST circuit
Shift solenoid valve ST

How to Fix the DTC P1790 2002 Toyota Echo?

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 2002 Toyota Echo 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 2002 Toyota Echo code?

Need more information on how to fix the P1790 2002 Toyota Echo code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P1790 2002 Toyota Echo code diagnosed by a professional: Find a repair shop in your area

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P1790 2002 Toyota Echo Code

1. What are the common symptoms of OBDII code P1790 on a 2002 Toyota Echo?

Common symptoms include difficulty shifting gears, harsh shifting, or even the transmission going into limp mode.

2. What does the OBDII code P1790 on a 2002 Toyota Echo indicate?

Code P1790 indicates a malfunction in the ST Solenoid Valve circuit of the transmission.

3. What are the possible causes of the ST Solenoid Valve Circuit Malfunction in a 2002 Toyota Echo?

Possible causes include a faulty ST solenoid valve, damaged wiring or connectors in the circuit, low transmission fluid level, or a malfunctioning Transmission Control Module (TCM).

4. How can I diagnose the ST Solenoid Valve Circuit Malfunction in my 2002 Toyota Echo?

Diagnosis typically involves checking the transmission fluid level, inspecting the wiring and connectors for damage, and using a scan tool to monitor the ST solenoid valve operation.

5. Can I continue driving my 2002 Toyota Echo with OBDII code P1790 present?

It is not recommended to continue driving with P1790 as it can lead to further transmission issues. It's best to address the problem promptly.

6. How can I repair the ST Solenoid Valve Circuit Malfunction in my 2002 Toyota Echo?

Repair options may include replacing the ST solenoid valve, repairing damaged wiring or connectors, ensuring proper transmission fluid levels, or reprogramming the TCM.

7. Is it possible to reset the OBDII code P1790 on a 2002 Toyota Echo without fixing the underlying issue?

While clearing the code may temporarily turn off the check engine light, it will not solve the root problem causing the malfunction.

8. Can a DIY enthusiast fix the ST Solenoid Valve Circuit Malfunction in a 2002 Toyota Echo?

Depending on the skill level and tools available, some DIY enthusiasts may be able to address the issue themselves, but it's recommended to consult a professional for complex transmission problems.

9. How much does it cost to repair the ST Solenoid Valve Circuit Malfunction in a 2002 Toyota Echo?

Repair costs can vary based on the specific cause of the issue, but it's advisable to budget for parts and labor expenses associated with transmission repairs.

10. How often does the ST Solenoid Valve Circuit Malfunction occur in a 2002 Toyota Echo?

While not extremely common, issues with the ST solenoid valve circuit can arise in older vehicles like the 2002 Toyota Echo, especially if regular maintenance has been neglected.