OBD-II diagnostic trouble code
P0703Caution
Torque Converter/Brake Switch B Circuit Malfunction
A secondary brake switch input used by the transmission (often for torque converter lock-up logic) has an electrical fault.
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Code names are compiled from open/standardized SAE and ISO references. Explanations, symptoms, causes and fixes are original. Covers generic (P0/C0/B0/U0) codes only — manufacturer-specific codes are planned for a future update.
Frequently asked questions
Can I drive with P0703?
You can usually keep driving with P0703, but don't put it off — the underlying cause can get worse or lead to further damage the longer it goes unaddressed. Get it diagnosed as soon as you reasonably can.
How much does it cost to fix P0703?
The cost varies too much by cause and vehicle to give a single figure here — a diagnosis will narrow it down.
What causes P0703?
Reviewed by Artyom SemenovAutomotive Editor · Fact-checked by Yauheni Kapliarchuk, Editor-in-Chief