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Home >> Chevrolet >> 2002 >> Blazer 4D Utility, 4WD, Part Time >> Repair and Diagnosis >> External Pages >> Different car >> Section 1567 (Engine Controls Diagnostic (DTC P0068 To DTC P0174) -- 5.7L) >> Diagnosis >> DTC P0106 >> Test Description

Test Description

WARNING: This page is about a different car, the 2004 Chevrolet Corvette. 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.

  1. 4:  This step tests the ability of the MAP sensor to correctly indicate BARO.
  2. 6:  This step tests the ability of the MAP sensor to respond to an increase in engine vacuum.
  3. 8:  This step tests for a proper MAP sensor pressure with an applied vacuum.
DTC P0106

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 Inspect for the following conditions:
  • Vacuum hoses that are disconnected, damaged, or incorrectly routed
  • Manifold absolute pressure (MAP) sensor seal that is missing or damaged
  • Restrictions in the MAP sensor vacuum source
  • Intake manifold vacuum leaks

Did you find and correct the condition?		 - Go to Step 21  Go to Step 3 
3
IMPORTANT: The vehicle used for the comparison is not limited to the same type of vehicle as is being serviced. A vehicle known to provide an accurate reading is acceptable.
Do you have access to another vehicle in which the MAP sensor pressure can be observed with a scan tool?		 - Go to Step 4  Go to Step 5 
4 
  1. Turn ON the ignition, with the engine OFF.
  2. Observe the MAP sensor pressure with a scan tool.
  3. Observe the MAP sensor pressure in the known good vehicle with a scan tool.
  4. Compare the values.
Is the difference between the values less than the specified value?		 3 kPa Go to Step 6  Go to Step 11 
5
IMPORTANT: The Altitude vs. Barometric Pressure table indicates a pressure range for a given altitude under normal weather conditions. Weather conditions consisting of very low or very high pressure and/or very low or very high temperature may cause a reading to be slightly out of range.
  1. Turn ON the ignition, with the engine OFF.
  2. Observe the MAP sensor pressure with a scan tool. Refer to Altitude vs Barometric Pressure .
  3. The MAP sensor pressure should be within the range specified for your altitude.
Does the MAP sensor indicate the correct barometric pressure?		 - Go to Step 6  Go to Step 11 
6 
  1. Turn OFF the ignition.
  2. Remove the MAP sensor from the intake manifold. Refer to Manifold Absolute Pressure (MAP) Sensor Replacement . Leave the MAP sensor connected to the electrical harness.
  3. Connect a J 23738-A  Mityvac to the MAP sensor.
  4. Turn ON the ignition, with the engine OFF.
  5. Observe the MAP sensor pressure with a scan tool.
  6. Apply vacuum to the MAP sensor with the J 23738-A  until 5 inch Hg is reached.
Does the MAP sensor pressure change?		 - Go to Step 7  Go to Step 11 
7
  1. Observe the MAP sensor pressure with the scan tool.
  2. Apply vacuum to the MAP sensor with the J 23738-A  in 1 inch Hg increments until 15 inches Hg is reached. Each 1 inch Hg should decrease MAP sensor pressure by 3-4 kPa.
Is the decrease in MAP sensor pressure consistent?		 - Go to Step 8  Go to Step 11 
8 
  1. Observe the MAP sensor pressure with the scan tool.
  2. Apply vacuum with the J 23738-A  until 20 inches Hg is reached.
Is the MAP sensor pressure less than the specified value?		 34 kPa Go to Step 9  Go to Step 11 
9
  1. Observe the MAP sensor pressure with the scan tool.
  2. Disconnect the J 23738-A  from the MAP sensor.
Does the MAP sensor pressure return to the original reading observed in Step 4 or Step 5?		 - Go to Step 10  Go to Step 19 
10 Inspect for the following conditions:
Did you find and correct the condition?		 - Go to Step 21  Go to Intermittent Conditions
11 Test for an intermittent and a poor connection at the MAP 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 21  Go to Step 12 
12
  1. Disconnect the MAP sensor harness connector.
  2. Turn ON the ignition, with the engine OFF.
  3. Measure the voltage from the 5-volt reference circuit of the MAP sensor to a good ground, with a DMM. Note the measurement as "Supply voltage".
  4. Connect a test lamp and a DMM in series between the 5-volt reference circuit and the low reference circuit of the MAP sensor at the harness connector.
  5. Measure the amperage with the DMM. Note the measurement as "Amperage".
Is the amperage equal to the specified value?		 0 mA Go to Step 16  Go to Step 13 
13
  1. Remove the DMM from the circuit.
  2. Connect the test lamp between the 5-volt reference circuit and the low reference circuit of the MAP sensor, at the harness connector.
  3. Measure the voltage from the 5-volt reference circuit at the test lamp to a good ground, with the DMM. Note the measurement as "Load voltage drop".
  4. Subtract the "Load voltage drop" from the "Supply voltage". Note the result as "Supply voltage drop".
  5. Divide the "Supply voltage drop" by the amperage.
Is the result more than the specified value?		 5 ohm Go to Step 15  Go to Step 14 
14
  1. Measure the voltage from the low reference circuit of the MAP sensor at the test lamp to a good ground, with the DMM. Note the result as "Low reference voltage drop".
  2. Divide the "Low reference voltage drop" by the amperage.
Is the result more than the specified value?		 5 ohm Go to Step 17  Go to Step 19 
15 Test the 5-volt reference circuit between the powertrain control module (PCM) and the MAP sensor for high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 21  Go to Step 18 
16 Test the low reference circuit between the PCM and the MAP sensor for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 21  Go to Step 18 
17 Test the low reference circuit between the PCM and the MAP sensor for high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 21  Go to Step 18 
18 Test for an intermittent and for a poor connection at the 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 21  Go to Step 20 
19 Replace the MAP sensor. Refer to Manifold Absolute Pressure (MAP) Sensor Replacement .
Did you complete the replacement?		 - Go to Step 21  -
20 Replace the PCM. Refer to Powertrain Control Module (PCM) Replacement .
Did you complete the replacement?		 - Go to Step 21  -
21
  1. Clear the DTCs with a scan tool.
  2. Turn OFF the ignition for 30 seconds.
  3. Start the engine.
  4. 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 22 
22 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
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