AutoCodes – Toyota – P1790 2000 Toyota Echo

P1790 2000 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 2000 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.

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Code Popularity 3,389

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

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

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P1790 2000 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 2000 Toyota Echo - ST Solenoid Valve Circuit Malfunction - AutoCodes.com — P1790 2000 Toyota Echo Code - ST Solenoid Valve Circuit Malfunction

What does this mean?

What are the Possible Causes of the DTC P1790 2000 Toyota Echo?

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

How to Fix the DTC P1790 2000 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 2000 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 2000 Toyota Echo code?

Need more information on how to fix the P1790 2000 Toyota Echo code? Get Access to Factory Service Manuals

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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 2000 Toyota Echo Code

What does the OBDII code P1790 mean for a 2000 Toyota Echo?

P1790 indicates a malfunction in the ST (Super Toyota) solenoid valve circuit, which is part of the automatic transmission control system.

What are the common symptoms associated with code P1790?

Common symptoms may include erratic shifting, slipping transmission, illuminated check engine light, and potentially poor acceleration.

What could cause the P1790 code to trigger in a 2000 Toyota Echo?

Possible causes include a faulty ST solenoid valve, wiring issues, poor electrical connections, or a malfunctioning transmission control module (TCM).

How can I diagnose the P1790 code in my Toyota Echo?

Start by visually inspecting the wiring and connectors related to the ST solenoid. Then, use an OBDII scanner to check for additional codes and monitor the solenoid operation.

What repairs are typically needed to fix the P1790 code?

Repairs may involve replacing the ST solenoid valve, repairing damaged wiring, or addressing issues with the transmission control module if it's found to be faulty.

Is it safe to drive my Toyota Echo with the P1790 code?

While it may be possible to drive short distances, it's advisable to avoid extended driving as it could lead to further transmission damage.

Can I clear the P1790 code without making repairs?

Yes, you can clear the code with an OBDII scanner, but if the underlying issue isn't fixed, the code will likely return.

How much might it cost to repair the P1790 issue?

Repair costs can vary widely, typically ranging from $100 for minor electrical issues to over $500 for solenoid replacement or TCM repairs.

Will the P1790 code affect my vehicle's fuel economy?

Yes, if the transmission isnâ€™t shifting properly due to the P1790 code, it can lead to decreased fuel efficiency.

Are there any preventative measures to avoid the P1790 code?

Regular maintenance, including checking transmission fluid levels, inspecting wiring, and keeping the transmission system clean, can help prevent issues that lead to this code.