P0700 – Transmission control system requests warning light

P0700 indicates a fault reported by transmission control, often described as a request for the malfunction indicator light. Additional transmission codes contain the more specific fault information.

Powertrain · Transmission control

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Meaning and affected system

The engine controller can store P0700 because transmission control has requested the warning light. A basic reader may display only this summary. The cause requires a diagnostic tool capable of accessing the transmission controller.

Possible causes

A fault stored by transmission control is the starting point for investigation.
Additional codes and actual vehicle findings determine which electrical, hydraulic or mechanical checks follow.
P0700 alone cannot reliably identify a faulty sensor, valve or control module.

Possible symptoms

The check engine light may illuminate.
Abnormal shifting or restricted transmission operation may occur; the particular response depends on the vehicle.

Useful diagnostic considerations

Have transmission-control codes and accompanying operating data read with suitable equipment.
If communication codes are present, establish whether the relevant modules can be reached.
Use the manufacturer’s diagnostic procedure for the accompanying fault, rather than treating P0700 as a repair instruction.

What this code does not prove

Neither a fluid change nor transmission-controller replacement follows from P0700 alone. If drive is lost or shifting becomes unpredictable, stop safely and arrange assistance.

Look up another fault code

Sources and interpretation

This explanation was editorially cross-checked against the technical sources below. Manufacturer documents concern particular vehicle applications; their thresholds and repair procedures must not be applied universally.

OBD-II code data: OBDex (CC0 1.0) · 196fddffb6ef

Editorial source review: 16 October 2026.

The causes listed are possibilities without a likelihood ranking. This page cannot replace diagnosis of the vehicle. A code alone confirms neither a failed component nor that continuing to drive is safe. The actual condition, warnings, handbook and applicable manufacturer diagnostics determine the next step.