P0069

DTC P0069

CIRCUIT DESCRIPTION
The barometric pressure (BARO) sensor is a transducer that varies resistance according to changes in altitude and atmospheric conditions. This gives the powertrain control module (PCM) an indication the current of barometric pressure. The PCM uses this information to calculate fuel delivery. The BARO sensor has a 5-volt reference circuit, a low reference circuit, and a signal circuit. The PCM supplies 5 volts to the BARO sensor on a 5-volt reference circuit, and provides a ground on a low reference circuit. The BARO sensor provides a voltage signal to the PCM on a signal circuit relative to the pressure changes. The PCM compares the BARO sensor to the manifold absolute pressure (MAP) sensor in order to monitor the BARO sensor operation. If the difference between the two sensors is more than a predetermined amount, DTC P0069 sets.

CONDITIONS FOR RUNNING THE DTC
- DTCs P0101, P0102, P0103, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0125, P0128, P0220, P0502, P0503, P2135, P2228, P2229 are not set.
- The ignition is ON.

CONDITIONS FOR SETTING THE DTC
- The PCM detects that the difference between the BARO sensor pressure and the MAP sensor pressure is more than 5 kPa when the ignition is ON before engine startup.

OR

- The difference between the BARO sensor pressure and the PCM predicted BARO is more than 60 kPa when the engine is running.
- The above conditions are met for 1 second.

ACTION TAKEN WHEN THE DTC SETS
- The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
- The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

CONDITIONS FOR CLEARING THE MIL/DTC
- The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
- A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
- A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
- Clear the MIL and the DTC with a scan tool.

TEST DESCRIPTION

Steps 1-7:

Steps 8-14:

Steps 15-20:

Steps 21-32:

The numbers below refer to the step numbers on the diagnostic table.
5. This step tests the ability of the BARO sensor to correctly indicate barometric pressure. The value shown for the BARO sensor varies with altitude and weather conditions.
7. This step tests the ability of the MAP sensor to correctly indicate barometric pressure.
8. This step tests for a sensor that is stuck in range.
14. This step calculates the resistance in the 5-volt reference circuit.
15. This step calculates the resistance in the low reference circuit.
18. This step calculates the resistance in the 5-volt reference circuit.
19. This step calculates the resistance in the low reference circuit.