Test Description

WARNING: This page is about a different car, the 2007 Chevrolet Cobalt. 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 MAP 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 P0108

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 P0651 set?	-	Go to DTC P0651	Go to Step 3
3	Observe the MAP Sensor parameter with a scan tool. Is the MAP Sensor parameter more than the specified value?	4.90 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	Turn ON the ignition, with the engine OFF. Disconnect the manifold absolute pressure (MAP) sensor electrical connector. Observe the MAP Sensor parameter with a scan tool. Is the MAP Sensor parameter less than the specified value?	0.20 V	Go to Step 6	Go to Step 7
6	Turn OFF the ignition. Connect a jumper wire between each of the terminals in the MAP sensor harness connector and the corresponding terminal at the MAP 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 MAP 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?	0.20 V	Go to Step 8	Go to Step 9
7	Test the MAP sensor signal circuit between the powertrain control module (PCM) and the MAP sensor for a short to voltage. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition?	-	Go to Step 13	Go to Step 10
8	Test the MAP sensor low reference circuit between the PCM and the MAP sensor for a high resistance or for an open. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition?	-	Go to Step 13	Go to Step 10
9	Test for an intermittent and for shorted terminals and for a poor connection at the MAP sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition?	-	Go to Step 13	Go to Step 11
10	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 13	Go to Step 12
11	Replace the MAP sensor. Refer to Manifold Absolute Pressure Sensor Replacement (SCIP) or Manifold Absolute Pressure Sensor Replacement (TMAP) . Did you complete the replacement?	-	Go to Step 13	-
12	Replace the PCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement?	-	Go to Step 13	-
13	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 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 - Vehicle	System OK