Skip to content
Language: EN
Download

P0703: Torque converter/brake switch B: circuit fault

The ECU is not getting a proper signal from the brake pedal switch used by the automatic gearbox; the switch itself is usually to blame.

Code P0703 at a glance
CodeP0703
SystemEngine and transmission
GroupP07xx, Transmission
TypeGeneric: it means the same on every make
Can you keep driving?With care

What P0703 means

The brake pedal switch tells the control units when you brake. Besides lighting the brake lights, it is used to unlock the torque converter in an automatic gearbox, release the selector from P and cancel cruise control. This code means the signal on circuit B of that switch does not make sense.

Most common causes

  • Brake pedal switch out of adjustment or faulty
  • Loose switch connector
  • Blown brake light fuse
  • Damaged switch wiring
  • ECU fault (uncommon)

Symptoms

  • Brake lights not working or staying on
  • Selector will not come out of P
  • Cruise control not working
  • Jerky feel when braking to a stop

Can you drive with P0703?

With care You can drive with care, but check the brake lights as soon as possible: if they do not work, drivers behind you will not see you braking.

How to check it

Ask someone to watch the brake lights while you press the pedal: if they do not light, or stay on when you release it, the pedal switch is the first suspect.

How to read and clear P0703 with Final OBD

Plug an OBD2 scanner in under the steering wheel, switch the ignition on and open Final OBD. Under Faults you’ll see P0703 with this same explanation and whether it’s confirmed, pending or permanent.

This code is usually stored by the gearbox control unit. With Free you read it for nothing with its short description, because Free reads every control unit; with Pro you also get the full explanation, how the car was running when it was logged and clearing.

Clearing the code only turns the light off: if the cause is still there, it comes back. Clear it once it’s fixed, and not right before the ITV. It’s all in how to read and clear fault codes and in the ITV and OBD.

Similar codes

P0703 is a generic code, so it means the same on any make, for example on Abarth, Citroën, Hyundai, Mini, Seat, Volvo. See what Final OBD does on your car in makes and models.

What does code P0703 mean?

The brake pedal switch tells the control units when you brake. Besides lighting the brake lights, it is used to unlock the torque converter in an automatic gearbox, release the selector from P and cancel cruise control. This code means the signal on circuit B of that switch does not make sense.

Can you drive with P0703?

You can drive with care, but check the brake lights as soon as possible: if they do not work, drivers behind you will not see you braking.

How do you clear P0703?

With an OBD2 scanner and an app like Final OBD, which clears it for free if it’s stored by the engine control unit. But clearing it only turns the light off: if the cause isn’t fixed, P0703 comes back.