Test Description

WARNING: This page is about a different car, the 2004 Pontiac Grand Prix. However, it is still accessible from the selected car via links, so may be relevant.

The numbers below refer to the step numbers on the diagnostic table.

2: The BARO sensor 5-volt reference circuit is shared with other sensors. If DTC P0651 is set, this indicates a shorted 5-volt reference circuit or a shorted component, and should be diagnosed first.

DTC P2228

Step	Action	Values	Yes	No
Schematic Reference: Engine Controls Schematics Connector End View Reference: Powertrain Control Module (PCM) Connector End Views or Engine Controls Connector End Views
1	Did you perform the Diagnostic System Check-Engine Controls?	-	Go to Step 2	Go to Diagnostic System Check - Engine Controls
2	Turn ON the ignition, with the engine OFF. Monitor the DTC information with a scan tool. Does the scan tool indicate that DTC P0651 is also set?	-	Go to DTC P0651 (With Supercharger) or DTC P0651 (Without Supercharger)	Go to Step 3
3	Observe the barometric pressure (BARO) sensor pressure with a scan tool. Does the scan tool indicate that the pressure is less than the specified value?	18 kPa	Go to Step 5	Go to Step 4
4	Observe the Freeze Frame/Failure Records for this DTC. Turn OFF the ignition for 30 seconds. Start the engine. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records. Did the DTC fail this ignition?	-	Go to Step 5	Go to Intermittent Conditions
5	Test for an intermittent and for a poor connection at the BARO sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?	-	Go to Step 13	Go to Step 6
6	Disconnect the BARO sensor electrical connector. Turn ON the ignition, with the engine OFF. Measure the voltage from the 5-volt reference circuit of the BARO sensor to a good ground with a DMM. Is the voltage more than the specified value?	4.8 V	Go to Step 7	Go to Step 8
7	Connect a 3-amp fused jumper wire between the 5-volt reference circuit of the BARO sensor and the signal circuit of the BARO sensor. Observe the BARO parameter with the scan tool. Is the pressure more than the specified value?	198 kPa	Go to Step 11	Go to Step 9
8	Test the 5-volt reference circuit of the BARO sensor for an open. Refer to Testing for Continuity and Wiring Repairs in Wiring Systems. Did you find and correct the condition?	-	Go to Step 13	Go to Step 10
9	Test the signal circuit of the BARO sensor for an open or a short to ground. Refer to Testing for Continuity and Wiring Repairs in Wiring Systems. Did you find and correct the condition?	-	Go to Step 13	Go to Step 10
10	Test for an intermittent and for a poor connection at the powertrain control module (PCM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?	-	Go to Step 13	Go to Step 12
11	Replace the BARO sensor. Refer to Barometric Pressure (BARO) Sensor Replacement . Did you complete the replacement?	-	Go to Step 13	-
12	Replace the PCM. Refer to Powertrain Control Module (PCM) Replacement . Did you complete the replacement?	-	Go to Step 13	-
13	Clear the DTCs with a scan tool. Turn OFF the ignition for 30 seconds. Start the engine. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records. Did the DTC fail this ignition?	-	Go to Step 2	Go to Step 14
14	Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?	-	Go to Diagnostic Trouble Code (DTC) List	System OK