Test Procedure

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	DQ1	DQ1	DQ1
P0108	DQ1	DQ1	DQ1
P0109	DQ1

DQ1 DTC P0106, P0107, P0108 AND P0109: CHECK BARO PID

NOTE: Most weather reports are a local barometric pressure that has been corrected to sea level. However, the BARO PID reports the actual barometric pressure for the altitude where the vehicle is being diagnosed. Local weather conditions (high or low pressure areas) will change the local barometric pressure by several inches of mercury.

Verify the BARO sensor is connected. If not, repair as necessary.
Key in ON position.
Access the BARO PID.
CHECK that the BARO PID is approximately the same as the barometric pressure reading for the location, day and altitude where the vehicle is being diagnosed.
Compare the PID readings with the chart.
The BARO PID values in Keep Alive Memory require updating at high throttle openings. If the vehicle is driven down from higher altitudes for diagnosing, carry out 3 or 4 heavy accelerations at greater than half-throttle to allow the BARO PID to update.
The BARO PID must be within +/ - 0.9 volt (+/- 2 in. Hg.) of the altitude value in the BAROMETRIC PRESSURE REFERENCE CHART (at the beginning of this pinpoint test).
Make BARO PID comparisons to the BAROMETRIC PRESSURE REFERENCE CHART or daily airport barometric pressure reports, if available.

Does the PID reading compare with that of the chart?

Yes	No
Unable to identify the fault at this time. GO to PINPOINT TEST Z step 1 .	GO to DQ3.

DQ2 CHECK FOR THE INITIAL DTCS PRESENT

Review the original DTCs that brought you to the above pinpoint test step.

Is DTC P0108 present?

Yes	No
GO to DQ8.	GO to DQ3.

DQ3 CHECK THE VREF VOLTAGE TO THE BARO SENSOR

Disconnect the BARO sensor harness connector.
Measure the voltage between:

( + ) BARO Connector, Harness Side	( - ) BARO Connector, Harness Side
VREF - Pin 2	SIGRTN - Pin 1

Is the voltage between 4 V - 6 V?

Yes	No
Key in OFF position. GO to DQ6.	Key in OFF position. GO to DQ4.

DQ4 CHECK THE VREF CIRCUIT FOR AN OPEN

Disconnect the PCM.
Measure the resistance between:

( + ) PCM Connector, Harness Side	( - ) BARO Connector, Harness Side
VREF	VREF - Pin 2

Is the resistance less than 5 ohms?

Yes	No
GO to DQ5.	REPAIR the open circuit.

DQ5 CHECK FOR A VREF CIRCUIT SHORT TO GROUND

Measure the resistance between:

( + ) PCM Connector, Harness Side	( - ) PCM Connector, Harness Side
VREF	SIGRTN
VREF	PWRGND

Are both resistances greater than 10K ohms?

Yes	No
GO to DQ6.	REPAIR the short circuit.

DQ6 CHECK THE BARO SIGNAL AND THE SIGRTN CIRCUIT FOR AN OPEN

PCM disconnected.
Measure the resistance between:

( + ) PCM Connector, Harness Side	( - ) BARO Connector, Harness Side
BARO	BARO - Pin 3
SIGRTN	SIGRTN - Pin 1

Are the resistances less than 5 ohms?

Yes	No
GO to DQ7.	REPAIR the open circuit.

DQ7 CHECK THE BARO CIRCUIT FOR A SHORT TO GROUND

Measure the resistance between:

( + ) PCM Connector, Harness Side	( - ) PCM Connector, Harness Side
BARO	SIGRTN
BARO	PWRGND

Are all the resistances greater than 10K ohms?

Yes	No
REPLACE the BARO. If the concern is still present, REPLACE the PCM. REFER to FLASH ELECTRICALLY ERASEABLE PROGRAMMABLE READ ONLY MEMORY - FLASH EEPROM .	REPAIR the short circuit.

DQ8 DTC P0108: INDUCE OPPOSITE CODE

Disconnect the BARO sensor harness connector.
Key in ON position.
CHECK for DTCs.

Is DTC P0107 present?

Yes	No
Key in OFF position. REPLACE the BARO sensor.	Key in OFF position. GO to DQ9.

DQ9 CHECK THE BARO SIGNAL FOR A SHORT TO POWER

Disconnect the PCM.
Measure the resistance between:

( + ) PCM Connector, Harness Side	( - ) PCM Connector, Harness Side
VPWR	BARO

Is the resistance greater than 10K ohms?

Yes	No
REPLACE the PCM. REFER to FLASH ELECTRICALLY ERASEABLE PROGRAMMABLE READ ONLY MEMORY - FLASH EEPROM .	REPAIR the short circuit.