P0703 on Ford
Brake Switch B Circuit Malfunction
P0703 on Ford vehicles indicates brake switch b circuit malfunction. Au7o has documented this code across 1 Ford model — most commonly on Bronco. This code means the engine/transmission computer detected an out-of-range or implausible signal from the brake switch (circuit B). The brake switch tells the PCM/TCM when the brakes are applied, which affects cruise control, torque converter lockup, and certain shift and idle strategies. A faulty signal can cause issues like cruise control not working, harsh shifts, or the converter not unlocking. Typical repair costs on Ford range from $2,200 to $4,000, depending on the specific model and root cause.
Common Causes of P0703
- •Faulty brake light switch
- •Misadjusted brake switch
- •Open or shorted brake switch wiring
- •Corroded or loose connector at the switch
- •Blown brake circuit fuse
- •PCM/TCM input fault
P0703 on Ford by Model
Ford Bronco(1 issue)
- E4OD Automatic Transmission Failure (Heat and Brake-Circuit Related)1990-1996
The electronically controlled E4OD 4-speed automatic behind the V8s is notorious for failing, especially with age, towing, off-road use, or an undersized/overheated cooler. It is heat-sensitive, and a well-documented secondary killer is the brake-light circuit: the PCM watches brake-light voltage to unlock the torque converter, so a shorted/failed brake light, brake-switch wiring, four-way flasher activity, or non-resistive LED bulb swap can make the converter cycle improperly and burn up the transmission. Owners also report the O/D-off light flashing (stored fault), harsh or missing shifts, and failure to shift out of high range from a lost power feed.
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View P0703 across all makes →Frequently Asked Questions
What does P0703 mean on Ford?▼
P0703 stands for "Brake Switch B Circuit Malfunction." This code means the engine/transmission computer detected an out-of-range or implausible signal from the brake switch (circuit B). The brake switch tells the PCM/TCM when the brakes are applied, which affects cruise control, torque converter lockup, and certain shift and idle strategies. A faulty signal can cause issues like cruise control not working, harsh shifts, or the converter not unlocking. On Ford specifically, this code is documented across 1 model.
What causes P0703 on Ford vehicles?▼
Common causes on Ford: Faulty brake light switch, Misadjusted brake switch, Open or shorted brake switch wiring, Corroded or loose connector at the switch, Blown brake circuit fuse. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0703 on a Ford?▼
Repair costs on Ford range from $2,200 to $4,000, depending on the specific model and root cause.
Which Ford models have P0703 documented?▼
Au7o has documented P0703 on 1 Ford model: Bronco.