Mike's Workshop Manuals: Service manuals for every vehicle
Home >> Chevrolet >> 2005 >> Epica LS >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - 2.5L (LBK) - DTC P0030 To DTC P0154 >> DTC P0106 >> Test Description

Test Description

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

  1. 3:  This step determines if the condition is present.
  2. 6:  This step tests the MAP sensor's ability to correctly indicate barometric pressure. The value shown for the MAP sensor varies with altitude.
  3. 7:  This step tests the MAP sensor's ability to respond to an increase in engine vacuum.
  4. 10:  This step tests the MAP sensor's ability to respond to a sudden decrease in vacuum.
Step Action Values Yes No
Schematic Reference:  Engine Controls Schematics Connector End View Reference:  Engine Controls Connector End Views  or Engine Control Module (ECM) 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 Is DTC P0102 also set? - Go to DTC P0102  Go to Step 3 
3 
IMPORTANT: If you were sent here from DTC P0101, proceed to step 4.
  1. Start the engine.
  2. Allow the engine to idle for 5 minutes.
  3. Observe the Diagnostic Trouble Code (DTC) Information with a scan tool.
Does the DTC fail this ignition cycle?		 - Go to Step 5  Go to Step 4 
4
  1. Observe the Freeze Frame and/or the Failure records data for this DTC.
  2. Turn OFF the ignition for 30 seconds.
  3. Start the engine.
  4. Operate the vehicle within the Conditions for Running the DTC. You also may operate the vehicle within the conditions that you observed from the Freeze Frame and/or the Failure records data.
Does the DTC fail this ignition cycle?		 - Go to Step 5  Go to Diagnostic Aids
5
  1. Turn ON the ignition, with the engine OFF.
  2. Observe the TP sensor voltage parameter with a scan tool.
  3. Press the accelerator pedal from a closed throttle position, to a wide open throttle position.
Does the TP sensor voltage parameter go from above the specified value to below the specified value?		 Above 4.0 V to below 1.0 V Go to Step 6  Go to DTC P0121 
6 
  1. Turn ON the ignition, with the engine OFF.
  2. Observe the MAP sensor kPa parameter with a scan tool.
  3. Record the MAP sensor kPa parameter that you observed.
  4. Compare the MAP sensor kPa parameter to a known good vehicle.
Is the MAP sensor kPa parameter within the specified value of the known good vehicle?		 3 kPa Go to Step 7  Go to Step 11 
7 
  1. Observe the MAP sensor voltage parameter with a scan tool.
  2. Start the engine.
Does the MAP sensor voltage parameter change value after you started the engine?		 - Go to Step 8  Go to Step 11 
8
  1. Turn OFF the ignition.
  2. Remove the MAP sensor from the vacuum source, but do not disconnect the electrical harness. Refer to Manifold Absolute Pressure (MAP) Sensor Replacement .
  3. Connect a Vacuum Pump to the MAP sensor.
  4. Turn ON the ignition, with the engine OFF.
  5. Observe the MAP sensor kPa as you SLOWLY apply 1 inch Hg of vacuum at a time. Each inch of vacuum should result in a 3-4 kPa drop in the MAP sensor display.
  6. Observe the MAP sensor kPa display for a abrupt change while increasing vacuum up to 20 inches Hg.
Does the scan tool indicate that the MAP sensor value changes smoothly through the entire range of the test?		 - Go to Step 9  Go to Step 19 
9 Observe the MAP sensor kPa display with 20 inches Hg of vacuum applied to the MAP sensor.
Does the scan tool indicate that the MAP sensor kPa is less than the specified value?		 34 kPa Go to Step 10  Go to Step 11 
10  Disconnect the MAP sensor from the hand vacuum pump. The MAP sensor kPa should return to the value observed in step 6.
Does the MAP sensor kPa return to the original value that you observed in step 6?		 - Go to Diagnostic Aids Go to Step 19 
11
  1. Turn OFF the ignition.
  2. Disconnect the MAP sensor electrical connector. Refer to Manifold Absolute Pressure (MAP) Sensor Replacement .
  3. Turn ON the ignition, with the engine OFF.
  4. Observe the MAP sensor voltage parameter with a scan tool.
Does the scan tool indicate that the MAP sensor voltage is more than the specified value?		 0.1 V Go to Step 17  Go to Step 12 
12
  1. Connect a 3-amp fused jumper wire between the 5-volt reference circuit of the MAP sensor and the signal circuit of the MAP sensor.
  2. Observe the MAP sensor voltage parameter with a scan tool.
Is the voltage more than the specified value?		 4.8 V Go to Step 13  Go to Step 18 
13
  1. Remove the fused jumper wire.
  2. Measure the voltage from the 5-volt reference circuit of the MAP sensor to a good ground.
Is the voltage more than the specified value?		 5.5 V Go to Step 14  Go to Step 15 
14 Test the 5-volt reference circuit of the MAP sensor for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 23  Go to Step 20 
15
IMPORTANT: All electrical components and accessories must be turned OFF.
  1. Turn OFF the ignition for 60 seconds to allow the control modules to power down before proceeding.
  2. Measure the resistance from the low reference circuit of the MAF sensor to a good ground with a DMM. Refer to Circuit Testing in Wiring Systems.
Is the resistance less than the specified value?		 2 Ω Go to Step 19  Go to Step 16 
16 Test the low reference circuit of the MAP sensor for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 23  Go to Step 20 
17 Test the signal circuit of the MAP sensor for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 23  Go to Step 20 
18 Test the signal circuit and the 5-volt reference circuit of 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 23  Go to Step 20 
19 Test for an intermittent and for 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 23  Go to Step 21 
20 Test for an intermittent and for a poor connection at the ECM. 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 23  Go to Step 22 
21 Replace the MAP sensor. Refer to Manifold Absolute Pressure (MAP) Sensor Replacement .
Did you complete the replacement?		 - Go to Step 23  -
22 Replace the ECM. Refer to Engine Control Module (ECM) Replacement .
Did you complete the replacement?		 - Go to Step 23  -
23
  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 24 
24 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
scientia non olet · About Mike's Workshop Manuals