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Test DQ: Barometric Pressure Sensor: Testing

NOTE: Proceed to DTC testing steps listed in FAULT CODE SETTING CONDITION  table of fault code setting condition.
FAULT CODE SETTING CONDITION

Fault Code KOEO KOER Continuous Memory
P0106  DQ1  DQ1  DQ1
P0107 1   DQ1  DQ1  DQ1
P0108 1   DQ1  DQ1  DQ1
P0109  DQ1  DQ1  DQ1
(1)
For engines with a MAP or TMAP sensor see FAULT CODE SETTING CONDITION .
    NOTE: For additional testing information, see DIAGNOSTIC AIDS .
    NOTE: If local barometric pressure is not corrected to sea level or cannot be obtained, check a known good vehicle BARO sensor PID value to determine actual barometric pressure. Local weather conditions (high or low pressure areas) will change local barometric pressure by several inches of mercury plus or minus 0.9 volt (plus or minus 2 in. Hg).

  1. 1) For KOEO, KOER & Continuous Memory DTC P0106, P0107, P0108 Or P0109: Check BARO PID
    DTC P0106 indicates BARO sensor reference voltage is not within calibrated limit of 4-6 volts. DTC P0107 indicates BARO sensor reference voltage fell below calibrated limit of .25 volt. DTC P0108 indicates BARO sensor reference voltage exceeded calibrated limit of 5 volts. DTC P0109 indicates intermittent BARO sensor signal failure. Possible causes for these faults are:
    • VREF Circuit Open, Shorted To Ground Or VPWR
    • BARO Signal Shorted To VPWR
    • Faulty BARO Sensor
    • Faulty PCM

    Ensure BARO sensor is connected properly. Obtain local barometric pressure measurement. Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). Turn ignition switch to ON position. Using scan tool, access BARO PID from PID/DATA MONITOR & RECORD menu. Compare BARO PID readings with specifications in BARO SENSOR SPECIFICATIONS  table. If BARO PID value is within specification, concern is not present at this time, go to TEST Z, step 1) . If BARO PID value is not within specification, go to next step. If BARO PID value is not within specification and DTC P0108 was retrieved, go to step  7).

  2. 2) Check VREF Voltage To BARO Sensor

    Disconnect BARO sensor connector. Using a DVOM, measure voltage between VREF and SIG RTN circuits at BARO sensor harness connector. See Figure. If voltage is 4-6 volts, go to step  5). If voltage is not 4-6 volts, go to next step.

  3. 3) Check VREF Circuit For Open

    Using a DVOM, measure resistance of VREF circuit between PCM harness connector and BARO sensor harness connector. See Figure. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open VREF circuit.

  4. 4) Check For VREF Circuit Short To Ground

    Using a DVOM, measure resistance between VREF circuit, and SIG RTN circuit at PCM harness connector, and negative battery terminal. See Figure. If either resistance measurement is 10 k/ohms or less, repair short in affected circuit. If both resistance measurements are more than 10 k/ohms, go to next step.

  5. 5) Check BARO SIG & SIG RTN Circuit For Open

    Using a DVOM, measure resistance of BARO SIG and SIG RTN circuits between PCM harness connector and BARO sensor harness connector. See Figure. If either resistance measurement is 5 ohms or more, repair open circuit. If both resistance measurements are less than 5 ohms, go to next step.

  6. 6) Check BARO Circuit For Short To Ground

    Using a DVOM, measure resistance between BARO circuit, and SIG RTN circuit at PCM harness connector, and negative battery terminal. See Figure. If both resistance measurements are more than 10 k/ohms, replace BARO sensor. If concern is still present, replace PCM. If either resistance measurement is 10 k/ohms or less, repair short in affected circuit.

  7. 7) DTC P0108: Induce Opposite Code

    Disconnect BARO sensor connector. Turn ignition switch to ON position. Check for DTCs. If DTC P0107 is present, replace BARO sensor. If DTC P0107 is not present, go to next step.

  8. 8) Check BARO SIG For Short To Power

    Turn ignition switch to OFF position. Using a DVOM, measure resistance between BARO SIG and VPWR circuits at PCM harness connector. See Figure. If resistance measurement is more than 10 k/ohms, replace PCM. If resistance measurement is 10 k/ohms or less, repair short to VPWR in BARO SIG circuit.
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