matchhead

I have a P2229 Barometric Pressure (BARO) Sensor Circuit High Voltage code. I have checked and I cant find anything unplugged, or damaged, any ideas on what to check before I buy a new MAP sensor.

matchhead

bump, anyone??

Gene Culley

iTrader: (1)

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Service Information
2007 Chevrolet Cobalt | Cobalt, G5 (VIN A) Service Manual | Document ID: 1589343
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DTC P2229
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 of the current 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 monitors the BARO sensor signal for voltage outside of the normal range. If the PCM detects a BARO sensor signal voltage that is excessively high, DTC P2229 sets.

DTC Descriptor
This diagnostic procedure supports the following DTC:

DTC P2229 Barometric Pressure (BARO) Sensor Circuit High Voltage

Conditions for Running the DTC
• The ignition is ON.

OR

The engine is cranking or running.

• This DTC runs continuously within the enabling conditions.

Conditions for Setting the DTC
The PCM detects that the BARO signal voltage is more than 4.5 volts for more than 8 seconds.

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
The number below refers to the step number on the diagnostic table.

2.The BARO sensor 5-volt reference circuit is shared with other sensors. If DTC P0641 is set, this indicates a shorted 5-volt reference circuit or a shorted component and should be diagnosed first.

Step
Action
Values
Yes
No

Schematic Reference: Engine Controls Schematics

Connector End View Reference: Powertrain Control Module Connector End Views or Engine Controls Connector End Views

1
Did you perform the Diagnostic System Check - Vehicle?
--
Go to Step 2
Go to Diagnostic System Check - Vehicle

2
•Turn ON the ignition, with the engine OFF.
•Observe the DTC Information with the scan tool.
Is DTC P0641 set?
--
Go to Diagnostic Trouble Code (DTC) List - Vehicle
Go to Step 3

3
Observe the BARO parameter with a scan tool.

Is the BARO parameter more than the specified value?
4.5 V
Go to Step 5
Go to Step 4

4
•Observe the Freeze Frame/Failure Records for this DTC.
•Turn OFF the ignition for 90 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 Record.
Did the DTC fail this ignition?
--
Go to Step 5
Go to Testing for Intermittent Conditions and Poor Connections

5
Important: The connectors for the following sensors are of the same configuration but are not interchangeable.

•Observe the engine controls schematics for the barometric pressure (BARO) sensor and for the supercharger inlet pressure (SCIP) sensor and note the circuit colors.
•Inspect the wiring harness of the BARO sensor for the proper connection.
•Inspect the wiring harness of the SCIP sensor for the proper connection.
Did you find and correct the condition?
--
Go to Step 14
Go to Step 6

6
•Turn ON the ignition, with the engine OFF.
•Disconnect the BARO sensor electrical connector.
•Observe the BARO parameter with a scan tool.
Is the BARO parameter less than the specified value?
0.2 V
Go to Step 7
Go to Step 8

7
•Turn OFF the ignition.
•Connect a jumper wire between each of the terminals in the BARO sensor harness connector and the corresponding terminal at the BARO sensor. Refer to Using Connector Test Adapters .
•Turn ON the ignition, with the engine OFF.
•Measure the voltage from the low reference circuit of the BARO sensor at the jumper wire terminal to a good ground with a DMM. Refer to Measuring Voltage Drop .
Is the voltage more than the specified value?
0.2 V
Go to Step 9
Go to Step 10

8
Test the BARO sensor signal circuit between the powertrain control module (PCM) and the BARO sensor for a short to voltage. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?
--
Go to Step 14
Go to Step 11

9
Test the low reference circuit between the PCM and the BARO sensor for high resistance or for an open. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?
--
Go to Step 14
Go to Step 11

10
Test for an intermittent and for shorted terminals and for a poor connection at the BARO sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?
--
Go to Step 14
Go to Step 12

11
Test for an intermittent and for shorted terminals and for a poor connection at the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?
--
Go to Step 14
Go to Step 13

12
Replace the BARO sensor. Refer to Barometric Pressure Sensor Replacement .

Did you complete the replacement?
--
Go to Step 14
--

13
Replace the PCM. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?
--
Go to Step 14
--

14
•Clear the DTCs with a scan tool.
•Turn OFF the ignition for 90 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 15

15
Observe the Capture Info with a scan tool.

Are there any DTCs that have not been diagnosed?
--
Go to Diagnostic Trouble Code (DTC) List - Vehicle
System OK

Š 2009 General Motors Corporation. All rights reserved.

matchhead

THANK YOU! now I have to read it

Gene Culley

iTrader: (1)

No problem at all.

matchhead

Thanks again, problem fixed!

The problem was 2 connectors were switched, problems of putting the motor back together.

Gene Culley

iTrader: (1)

That is good to hear. I'm glad it is fixed.