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Ricardo Hohl
Ricardo Hohl, ASE Master Certified Teck
Category: Car
Satisfied Customers: 4157
Experience:  Automotive instructor at Porter and Chester institute
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i installed a crank sensor on my 1999 4.3 olds bravada. It

Customer Question

i installed a crank sensor on my 1999 4.3 olds bravada. It has been not starting after getting warm..from time to time.....i replaced the coil..module....and now the crank sensor........how do i do a CRANKSHAFT VARIATION RELEARN procedure?
Submitted: 7 years ago.
Category: Car
Expert:  Randall C replied 7 years ago.
Hello, below are the directions for your reference but .. a scan tool is required to do this. It is possible it needs to be done since you have changed the parts mentioned

  1. Install the scan tool.
  2. Apply the vehicle's parking brake.
  3. Block the drive wheels.
  4. Close the hood.
  5. Place the vehicle's transmission in Park (AT) or Neutral (MT) .
  6. Idle the engine until the coolant temperature reaches 65°C (150°F) .
  7. Turn OFF all the accessories. IMPORTANT : If the CKP System Variation Learn Procedure cannot be completed successfully, refer to DTC P1336 Crankshaft Position (CKP) System Variation Not Learned for additional diagnostic information.
  8. Enable the Crankshaft Position System Variation Learn Procedure with the scan tool. IMPORTANT : After the ignition switch is turned to the CRANK position, the VCM must see a change in the state of brake switch (Released to Applied) to run the learn procedure. Also, the service brakes, not the parking brake, must be held throughout the duration of the learn procedure.
  9. Apply and hold the service brakes. IMPORTANT : While the learn procedure is in progress, release the throttle immediately when the engine starts to decelerate. The engine control is returned to the operator and the engine will respond to throttle position after the learn procedure is complete.
  10. Slowly raise the engine speed to 4000 RPM .
  11. Immediately release the Throttle when the engine speed decreases.
  12. Turn OFF the ignition for 15 seconds after the learn procedure is completed successfull
Customer: replied 7 years ago.

The car will not start. I cannot follow instructions given, specifically no. 6. I am in the backyear with an Actron scanner.
Expert:  Randall C replied 7 years ago.
I can only send the info you requested. there are several things that prevent from starting. You did not mention it is now not running. I will opt out to let another expert help you
Customer: replied 7 years ago.
i am losing my mind!!1999 olds bravada..4.3......will not start after driven a short distance..i have replaced the coil.module.crank sensor..map sensor.......any ideas?
Customer: replied 7 years ago.
i am losing my mind!!1999 olds bravada..4.3......will not start after driven a short distance..i have replaced the coil.module.crank sensor..map sensor.......any ideas?

Expert:  Ricardo Hohl replied 7 years ago.
you have not done a crank sensor relearn procedure thats why this truck wont start.read this TSB about the crank sensor problem and the cure for it and also the next page should have the relearn procedure but you will need a scanner to perform this task, make sure you copy or print this pages as soon as possible or they will be scramble by the web.
Notes

File In Section: 06 - Engine/Propulsion System

Bulletin No.: 00-06-04-014

Date: April, 2000

TECHNICAL

Subject:
No, Hard, or Slow Start, Backfire or "Kickback" During
Crank/Start, "Grinding" or Unusual Noises During Crank, DTC P0338
(Replace Crankshaft Position Sensor)

 

Models:
1999-2000 Cadillac Escalade
1995-2000 Chevrolet and GMC SIT Models
1996-2000 Chevrolet and GMC C/K, M/L, G, P Models
1996-2000 Oldsmobile Bravada
with 4.3 L, 5.0 L, 5.7 L or 7.4 L Engine
(VINs W, X, M, R, J RPOs L35, LF6, L30, L31, L29)

 

Condition:
Some customers may comment on one or more of the following conditions:

 

^Backfire during crank/start
^"Kickback" during crank/start
^"No" start
^"Slow" or "hard" start/crank
^"Grinding" or unusual noises during crank/start
^Cracked or broken engine block at the starter boss
^Broken starter drive housing
^Broken starter ring gear on flywheel
^Any combination of the above

 

Cause:
A condition may exist that allows the crankshaft position sensor to command up to 50 extra degrees of spark advance during engine cranking only. This in turn exposes the engine to higher than normal cylinder pressures which may result in an inoperative condition to the starter drive housing, the engine flywheel starter ring gear, or the engine block at the outside edge of the starter boss.

 

Correction:
Inspect for a stored powertrain DTC code P0338. This DTC will NOT illuminate the "Service Engine Soon" light. If this code is stored, the Crankshaft Position Sensor, P/N 10456607, MUST be replaced and the remaining components inspected for damage (engine block at the starter boss, the starter drive housing, and the engine flywheel starter ring gear).

 

Notice : When DTC code P0338 is set, failure to replace the Crankshaft Position Sensor could result in repeated inoperative conditions of the starter or flywheel.

 

Important : Some flywheel wear is normal; broken or missing teeth and/or cracks, are not normal.

 

Parts Information

Parts are currently available from GMSPO.

Warranty Information:

For vehicles repaired under warranty, use the table.

Notes
  1. Install the scan tool.
  2. Apply the vehicle's parking brake.
  3. Block the drive wheels.
  4. Close the hood.
  5. Place the vehicle's transmission in Park (AT) or Neutral (MT) .
  6. Idle the engine until the coolant temperature reaches 65°C (150°F) .
  7. Turn OFF all the accessories. IMPORTANT : If the CKP System Variation Learn Procedure cannot be completed successfully, refer to DTC P1336 Crankshaft Position (CKP) System Variation Not Learned for additional diagnostic information.
  8. Enable the Crankshaft Position System Variation Learn Procedure with the scan tool. IMPORTANT : After the ignition switch is turned to the CRANK position, the VCM must see a change in the state of brake switch (Released to Applied) to run the learn procedure. Also, the service brakes, not the parking brake, must be held throughout the duration of the learn procedure.
  9. Apply and hold the service brakes. IMPORTANT : While the learn procedure is in progress, release the throttle immediately when the engine starts to decelerate. The engine control is returned to the operator and the engine will respond to throttle position after the learn procedure is complete.
  10. Slowly raise the engine speed to 4000 RPM .
  11. Immediately release the Throttle when the engine speed decreases.
  12. Turn OFF the ignition for 15 seconds after the learn procedure is completed successfully.

 

 

 

 

Customer: replied 7 years ago.
that was not the reason the car would not start.....it had a broken wire on the fuel pump...i told you the car would not start...your answer did not help me one bit...im sorry....it was not a thoughtful answer......i do not feel that i owe you any cash.....sorry about the circumstances
Expert:  Ricardo Hohl replied 7 years ago.
ok, no problem i will close the window have a good night. next time make your question more clear you ask for a relearn procedure and that is what i send you, had it been something else then its different.

Edited by transman on 6/6/2010 at 5:20 AM EST

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