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Home >> Chevrolet >> 2002 >> Blazer 4D Utility, 4WD, Part Time >> Repair and Diagnosis >> External Pages >> Different car >> Section 1568 (Engine Controls Diagnostic (DTC P0172 To DTC P0455) -- 5.7L) >> Diagnosis >> DTC P0343 >> 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 number below refers to the step number on the diagnostic table.

  1. 4:  This step tests the CMP sensor and circuits from the CMP sensor to the PCM. If there is not duty cycle displayed or if the duty cycle is not within range there is a problem with the sensor or the circuits.
DTC P0343

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
  1. Start the engine.
  2. Observe the camshaft position (CMP) sensor high to low and low to high transition parameter with a scan tool.
Does the scan tool parameter increment?
- Go to Step 3  Go to Step 4 
3
  1. Observe the Freeze Frame/Failure Records 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 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 4  Go to Diagnostic Aids
  1. Disconnect the powertrain control module (PCM). Refer to Powertrain Control Module (PCM) Replacement .
  2. Jumper the low reference circuit of the CMP sensor from the PCM connector to a good ground. Refer to Using Connector Test Adapters in Wiring Systems.
  3. Jumper the 12-volt reference circuit of the CMP sensor from the PCM connector to battery voltage. Refer to Using Connector Test Adapters in Wiring Systems.
  4. Measure the DC duty cycle on the signal circuit of the CMP sensor at the PCM connector with a DMM while cranking the engine.
Is the duty cycle within the specified range?
45-50% Go to Step 10  Go to Step 5 
5
  1. Turn OFF the ignition.
  2. Connect the PCM. Refer to Powertrain Control Module (PCM) Replacement .
  3. Remove fuel pump relay using a J 43244  .
  4. Remove the intake manifold. Refer to Intake Manifold Replacement in Engine Mechanical.
  5. Disconnect the CMP sensor.
  6. Turn ON the ignition, with the engine OFF.
  7. Probe the signal circuit of the CMP sensor with a test lamp that is connected to a good ground. Refer to Probing Electrical Connectors in Wiring Systems.
Does the test lamp illuminate?
- Go to Step 7  Go to Step 6 
6
  1. Turn OFF the ignition.
  2. Jumper the CMP circuits from the CMP sensor to the CMP sensor harness connector. Refer to Using Connector Test Adapters in Wiring Systems.
  3. Turn ON the ignition with the engine OFF.
  4. Measure the Voltage Drop from the low reference circuit of the CMP sensor to a good ground with a DMM. Refer to Circuit Testing in Wiring Systems.
Is the voltage more than the specified value?
0.2 V Go to Step 8  Go to Step 9 
7 Test the CMP sensor signal circuit 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 15  Go to Step 10 
8 Test the low reference circuit 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 15  Go to Step 10 
9 Test for an intermittent and for a poor connection at the CMP 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 15  Go to Step 11 
10 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 15  Go to Step 14 
11
  1. Remove the CMP sensor. Refer to Camshaft Position (CMP) Sensor Replacement .
  2. Visually inspect the CMP sensor for the following conditions:
    • Physical damage
    • Loose or improper installation
Did you find and correct the condition?
- Go to Step 15  Go to Step 12 
12
  1. Visually inspect the CMP sensor reluctor ring for damage.
  2. If the CMP reluctor ring is damaged, refer to Camshaft and Bearings Cleaning and Inspection in Engine Mechanical.
Did you find and correct the condition?
- Go to Step 15  Go to Step 13 
13 Replace the CMP sensor. Refer to Camshaft Position (CMP) Sensor Replacement .
Did you complete the replacement?
- Go to Step 15  -
14 Replace the PCM. Refer to Powertrain Control Module (PCM) Replacement .
Did you complete the replacement?
- Go to Step 15  -
15
  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 16 
16 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