LEMON Manuals: Even more car manuals for everyone
Home >> Chevrolet >> 1998 >> Forward Control P30, 6.5 F, Standard >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 3 (Engine Controls - Tests W/Codes - 5.7L) >> Diagnostic Trouble Codes >> DTC P0338 - Crankshaft Position Sensor Circuit High Frequency >> Diagnostic Procedures

Diagnostic Procedures

WARNING: This page is about a different variant/trim than selected.
  1. Perform POWERTRAIN ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK , then go to next step.
  2. Check if engine starts. If engine starts, go to step 4). If engine does not start, go to next step.
  3. Clear DTCs. Crank engine for 10 seconds. Check if DTC P0338 resets. If DTC P0338 resets, go to next step. If DTC P0338 does not reset, see BASIC TESTING - 5.7L article.
  4. Install scan tool. Start engine and observe engine RPM on scan tool. If RPM fluctuates up to twice the expected RPM, go to step 14). If RPM does not fluctuate up to twice the expected RPM, go to next step.
  5. Disconnect crankshaft position sensor connector. Turn ignition on, with engine off. Using test light, probe signal circuit of crankshaft position sensor connector (engine harness side) to ground. If test light illuminates, go to next step. If test light does not illuminate, go to step 8).
  6. Connect test light between ground circuit and signal circuit of crankshaft position sensor connector (engine harness side). If test light illuminates, go to next step. If test light does not illuminate, go to step 12).
  7. Turn ignition off. Install Gray jumper wires from Connector Test Kit(J 35616-A) between engine harness connector and crankshaft position sensor. Start engine. Using DVOM, check voltage on signal circuit. If voltage reading is 2-3 volts, go to step 16). If voltage is not 2-3 volts, go to step 9).
  8. Turn ignition off. Disconnect VCM harness connector. Using test light connected to battery voltage, probe signal circuit of crankshaft position sensor connector (engine harness side). If test light illuminates, go to step 11). If test light does not illuminate, go to step 15).
  9. Check for open in signal circuit. If circuit is open, go to step 17). If circuit is okay, go to next step.
  10. Check for short to ground in signal circuit. If circuit is shorted, go to step 17). If circuit is okay, go to step 13).
  11. Repair short to ground in ignition feed circuit. After repairs, go to step 19).
  12. Repair open in ground circuit. After repairs, go to step 19).
  13. Check for poor connection at crankshaft position sensor. If a problem is found, go to step 17). If no problem is found, go to next step.
  14. Replace crankshaft position sensor. After replacing sensor, go to step 19).
  15. Check for open in ignition feed circuit. If ignition feed circuit is open, go to step 17). If circuit is okay, go to next step.
  16. Check for poor connection at VCM. If connection is faulty, go to next step. If connection is okay, go to step 18).
  17. Repair circuit as necessary. After repairs, go to step 19).
  18. Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to step 19).
  19. Using scan tool, select DTC, CLEAR INFO. Start and warm engine to normal operating temperature. Select DTC, SPECIFIC, then enter this DTC. Operate vehicle within the conditions for setting this DTC. If scan tool indicates that this test ran and passed, go to next step. If scan tool does not indicate that this test ran and passed, repeat step 2).
  20. Using scan tool, select CAPTURE INFO, REVIEW INFO. If any undiagnosed DTC(s) are displayed, go to applicable DTC test.
scientia non olet · About LEMON Manuals