OBD Guide
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B1978

Passengers Front Seat Down Switch Circuit Short To Battery

B1978 is an OBD-II diagnostic trouble code meaning: Passengers Front Seat Down Switch Circuit Short To Battery. Common causes: seat wiring harness damaged, seat down switch malfunction. Estimated repair cost: $33–111.

Severity
⚠️ Medium
Can you drive?
Do not drive — repair immediately
Approx. repair cost
$33–111 (est.)

Symptoms

  • Inability to lower the front passenger seat
  • Spontaneous seat movement
  • The airbag warning light is on (on some models)

Causes

  • Seat wiring harness damaged
  • Seat down switch malfunction
  • Short circuit in the circuit
  • Problems with the seat control unit

How to Fix

  1. Check the integrity of the seat wiring harness
  2. Test the switch circuit for a short circuit
  3. Check the functionality of the switch
  4. If necessary, replace the switch or repair the wiring harness
  5. Reset the error and check the system operation

Related codes

B1977B1979B1980

FAQ

What does the B1978 code mean?

B1978 is an OBD-II diagnostic trouble code that indicates: Passengers Front Seat Down Switch Circuit Short To Battery

What causes a B1978 error code?

The most common causes of B1978 include: Seat wiring harness damaged; Seat down switch malfunction; Short circuit in the circuit; Problems with the seat control unit.

How do I fix a B1978 diagnostic trouble code?

To fix B1978: Check the integrity of the seat wiring harness. Test the switch circuit for a short circuit. Check the functionality of the switch. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with B1978?

Do not drive — repair immediately

How much does it cost to fix B1978?

The estimated repair cost for B1978 is $33–111. Actual cost depends on your vehicle, location, and labor rates.

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See also: Russian version · NationStat