P2782 Generic (SAE) Basic entry

Downshift Switch Circuit Intermittent/Erratic

Updated 2026-10-02 · Fuel, air & emissions (P2)

Severity

Medium

Typical repair cost

40 – 350 EUR

System

Powertrain

What it means

P2782 is stored when the Downshift Switch signal drops out or jumps erratically for short periods. Intermittent faults are almost always connector, wiring or vibration related.

This entry is compiled automatically from the standard definition and typical diagnostic practice for this type of fault. A detailed, reviewed article is in preparation.

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Symptoms

Check engine light on
Rough or unstable idle
Hesitation or poor acceleration
Increased fuel consumption
Possible limp mode with reduced power

Common causes

Damaged, chafed or corroded wiring in the Downshift Switch circuit
Corroded, loose or water-damaged connector terminals
Failed Downshift Switch component (sensor, solenoid or actuator)
Poor ground connection for the module or component
Faulty control module driver (rare, confirm all else first)

How to diagnose

Read freeze frame data and note when the code set (cold start, under load, after rain)
Inspect the Downshift Switch connector for bent pins, corrosion and water; wiggle the harness with the engine running and watch live data
Measure supply voltage and ground at the connector with the key on
Check the signal wire for shorts to ground or battery and for continuity to the control module
Test or substitute the Downshift Switch only after wiring and connectors are confirmed good
Clear the code and complete a drive cycle to confirm the repair

Frequently asked questions

Can I keep driving with P2782?

Usually yes for a short time, but expect reduced performance or higher fuel use. Have it diagnosed within a few days.

Will clearing P2782 fix it?

No. Clearing only erases the stored code; it returns as soon as the monitor runs again unless the cause is repaired.

Related codes

P2779 P2780 P2781