DTCS 63/64, BARO Sensor Circuit High/Low (4L80-E With TCM): Notes

TCM supplies 5 volts to BARO sensor. As atmospheric pressure changes, resistance within BARO sensor also changes, modifying voltage on BARO sensor input signal. When atmospheric pressure is high (100 kPa) input signal voltage will also be high (about 4.5 volts). As atmospheric pressure decreases, input signal voltage also decreases. DTC 63 will set when:

• BARO sensor signal voltage greater than 4.9 volts.
• Conditions met for more than 2 seconds.

DTC 64 will set when:

• BARO sensor signal voltage less than 1.9 volts.
• Conditions met for more than 2 seconds. TCM will default to no altitude compensation of shift patterns.
  NOTE: Test numbers refer to numbers on diagnostic chart.

1. This verifies 5-volt supply to BARO sensor.
2. If entire circuit is okay, voltage measured will be 5 volts.