P0336 and no start after engine is warm

[Pete399]

Hey guys, just trying to see if anyone else ran in to this...
I swapped my tired beat down LQ9 for an overhauled LQ9 (with a bigger cam & springs) in my 03 Silverado SS and as I was working on dialing in my VE table the truck started to run like crap and then died. Checked DTC's and got P0336 for the crank sensor. Cleared it and still no start. After it sat for 15 mins it would start a ran fine, then as I was driving it home it did the same BS! I'm thinking the sensor is bad and getting heat soaked, or maybe I didn't clean up some of the grounds good enough. I tried to do CASE relearn after it sat a bit and would run but don't think I did it right cause I got no indication for it completing. What RPM does it have to be above? 4000?

[joecar]

I think the CKP sensor is going bad.

[chevy052500hd]

CKP System Variation Learn Procedure

1. Install a scan tool.
2. Monitor the powertrain control module (PCM) for DTCs with a scan tool. If other DTCs are set, except DTC P0315, refer to Diagnostic Trouble Code (DTC) List for the applicable DTC that set.
3. Select the crankshaft position (CKP) variation learn procedure with a scan tool.
4. The scan tool instructs you to perform the following:
1. Accelerate to wide open throttle (WOT).
2. Release throttle when fuel cut-off occurs.
3. Observe fuel cut-off for applicable engine.
4. Engine should not accelerate beyond calibrated RPM value.
5. Release throttle immediately if value is exceeded.
6. Block drive wheels.
7. Set parking brake.
8. DO NOT apply brake pedal.
9. Cycle ignition from OFF to ON.
10. Apply and hold brake pedal.
11. Start and idle engine.
12. Turn A/C OFF.
13. Vehicle must remain in Park or Neutral.
14. The scan tool monitors certain component signals to determine if all the conditions are met to continue with the procedure. The scan tool only displays the condition that inhibits the procedure. The scan tool monitors the following components:
* CKP sensors activity--If there is a CKP sensor condition, refer to the applicable DTC that set.
* Camshaft position (CMP) sensor activity--If there is a CMP sensor condition, refer to the applicable DTC that set.
* Engine coolant temperature (ECT)--If the ECT is not warm enough, idle the engine until the engine coolant temperature reaches the correct temperature.
5. Enable the CKP system variation learn procedure with a scan tool.

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 responds to throttle position after the learn procedure is complete.
6. Accelerate to WOT.
7. Release when the fuel cut-off occurs.
8. The scan tool displays Test In Progress.
9. The scan tool displays Learn Status: Learned this ignition. If the scan tool indicates that DTC P0315 ran and passed, the CKP variation learn procedure is complete. If the scan tool indicates DTC P0315 failed or did not run, refer to DTC P0315 . If any other DTCs set, refer to Diagnostic Trouble Code (DTC) List for the applicable DTC that set.
10. Turn OFF the ignition for 30 seconds after the learn procedure is completed successfully.
11. The CKP system variation learn procedure is also required when the following service procedures have been performed, regardless of whether DTC P0315 is set:
* A CKP sensor replacement
* An engine replacement
* A PCM replacement
* A harmonic balancer replacement
* A crankshaft replacement
* Any engine repairs which disturb the CKP sensor relationship

[chevy052500hd]

The crankshaft position (CKP) sensor signal indicates the crankshaft speed and position. The CKP sensor circuits are connected directly to the powertrain control module (PCM) and consists of the following circuits:

* The 12-volt reference circuit
* The low reference circuit
* The CKP sensor signal circuit

If the PCM detects that the CKP sensor signal is inconsistent for 2 seconds, DTC P0336 sets.
Conditions for Running the DTC

The engine is cranking or running.
Conditions for Setting the DTC

The PCM detects that the CKP sensor signal is inconsistent for 2 seconds.
Action Taken When the DTC Sets

* The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
* The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

Conditions for Clearing the MIL/DTC

* The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
* A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
* A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
* Clear the MIL and the DTC with a scan tool.

Step


Action


Yes


No

Schematic Reference: Engine Controls Schematics

Connector End View Reference: Engine Controls Connector End Views or Powertrain Control Module (PCM) 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


Important

If DTC P0335 is also set, diagnose DTC P0335 before proceeding with this DTC.

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 3


Go to Intermittent Conditions

3


Inspect all of the crankshaft position sensor (CKP) circuits for the following conditions:

* Wiring routed too closely to secondary ignition wires or components
* Wiring routed too closely to after-market add-on electrical equipment
* Wiring routed to closely to solenoids, relays, and motors
* Electromagnetic interference in the CKP sensor circuits

Did you find and correct the condition?


Go to Step 12


Go to Step 4

4


Test the 12-volt reference circuit for an intermittent condition or shorted to other circuits. Refer to Testing for Electrical Intermittents and Inducing Intermittent Fault Conditions in Wiring Systems.

Did you find and correct the condition?


Go to Step 12


Go to Step 5

5


Test the low reference circuit for an intermittent condition. Refer to Testing for Electrical Intermittents and Inducing Intermittent Fault Conditions in Wiring Systems.

Did you find and correct the condition?


Go to Step 12


Go to Step 6

6


Test the CKP sensor signal circuit for an intermittent condition. Refer to Testing for Electrical Intermittents and Inducing Intermittent Fault Conditions in Wiring Systems.

Did you find and correct the condition?


Go to Step 12


Go to Step 7

7


Test for an intermittent and for a poor connection at the CKP sensor. Refer to Testing for Intermittent and Poor Connections and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?


Go to Step 12


Go to Step 8

8


Test for an intermittent and for a poor connection at the powertrain control module (PCM). Refer to Testing for Intermittent and Poor Connections and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?


Go to Step 12


Go to Step 9

9


1. Remove the CKP sensor. Refer to Crankshaft Position (CKP) Sensor Replacement .
2. Inspect the CKP sensor for the following conditions:
* Physical damage
* Improper installation
* Excessive play or looseness
* Excessive air gap between the CKP sensor and the reluctor wheel
* Foreign material passing between the CKP sensor and the reluctor wheel
* Insufficient fuel

Did you find and correct the condition?


Go to Step 12


Go to Step 10

10


Inspect the reluctor wheel for the following conditions:

* Physical damage
* Improper installation
* Excessive endplay or looseness

Refer to Crankshaft and Bearings Cleaning and Inspection in Engine Mechanical.

Did you find and correct the condition?


Go to Step 12


Go to Step 11

11


Replace the CKP sensor. Refer to Crankshaft Position (CKP) Sensor Replacement .

Did you complete the replacement?


Go to Step 12


--

12


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 13

13


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