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Code 38, Brake Switch Stuck Off: Notes

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The normally closed brake switch supplies a 12-volt signal on circuit No. 420 to the PCM. The signal voltage is removed when brakes are applied. An incorrect brake signal may affect TCC and 4th gear operation.

Code 38 will set when circuit No. 420 has voltage, vehicle speed is greater than 20 MPH for 6 seconds, then between 5 MPH and 20 MPH for 6 seconds, for a complete total of 7 times.

NOTE: Test numbers refer to numbers on diagnostic chart. Display may vary depending upon manufacturer of scan tester. Display may read APPLIED, RELEASED, ON or OFF.
  1. This test checks for voltage at brake switch.
  2. This test simulates closed brake switch (brakes off).
  3. This test checks circuit No. 420 from brake switch to PCM.
  4. This test opens circuit No. 420 and simulates brakes being applied.
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