Performing a CKP relearn, or Crankshaft Position relearn, is sometimes necessary after certain repairs or modifications to your vehicle’s engine or ECU. This procedure ensures that your engine management system accurately reads the crankshaft position, which is crucial for proper engine timing and performance. If you’re using an Innova Scan Tool 3040, this guide will walk you through the process. It’s important to ensure certain conditions are met before you begin to guarantee a successful CKP relearn.
Prerequisites for CKP Relearn
Before starting the CKP relearn procedure with your Innova 3040 scan tool, it’s critical to verify that no Diagnostic Trouble Codes (DTCs) related to the crankshaft or camshaft position sensors, engine coolant temperature, or transmission range are present. The CKP relearn will not initiate if any of the following codes are active:
- P0335 Crankshaft Position (CKP) Sensor A Circuit
- P0336 Crankshaft Position (CKP) Sensor A Performance
- P0341 Camshaft Position (CMP) Sensor Performance Bank 1 Sensor A
- P0342 Camshaft Position (CMP) Sensor Circuit Low Bank 1 Sensor A
- P0343 Camshaft Position (CMP) Sensor Circuit High Bank 1 Sensor A
- P0117 Engine Coolant Temperature (ECT) Sensor Circuit Low
- P0118 Engine Coolant Temperature (ECT) Sensor Circuit High
- P1539 Air Conditioning (A/C) Clutch Feedback Circuit High Voltage
- P1546 Air Conditioning (A/C) Clutch Feedback Circuit Open
- P0705 Transmission Range (TR) Switch Circuit
- P0706 Transmission Range (TR) Switch Performance
- P1810 Transmission Fluid Pressure (TFP) Position Switch Circuit
- P1825 Internal Mode Switch-Invalid Range
In addition to the DTCs, the following conditions must also be met:
- Engine Coolant Temperature (ECT): Must be between 150°F and 220°F.
- RPM: Engine speed must be below 2400 RPM before starting.
- Throttle Position Sensor (TPS): Must read 0%.
- Vehicle Speed Sensor (VSS): Must read 0 mph.
- Parking Brake: Engage the parking brake.
- Transmission: Place the vehicle in Park or Neutral.
- Accessories: Turn off all unnecessary accessories (A/C, radio, lights).
- Brake Pedal: Keep your foot firmly on the brake pedal throughout the procedure.
CKP Relearn Procedure with Innova 3040 Scan Tool
Once you have confirmed all the prerequisites are met, follow these steps to perform the CKP relearn using your Innova 3040 scan tool:
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Connect Scan Tool: Plug in your Innova 3040 scan tool to the vehicle’s OBD-II port and turn the ignition key to the “ON” position (engine off). Click the green “connect” button on the scan tool interface.
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Navigate to DVT Tab: On the Innova 3040, go to the “DVT” (Diagnostic Test) tab.
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Select Controller: Choose the appropriate engine control module (ECM) or powertrain control module (PCM) from the controller selection menu.
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Activate Functions: Click the “Activate” button within the selected controller menu.
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Go to Learning Subtab: Navigate to the “Learning” or “Special Functions” subtab, depending on your Innova 3040’s menu layout.
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Initiate CASE Learn: Look for and select the “CASE Relearn” or “CKP Relearn” option. CASE stands for Crank Angle Sensor Error, which is another term for CKP relearn. Click to initiate the procedure.
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Increase RPM: The scan tool will instruct you to quickly open the throttle to increase the engine RPM above 4000 RPM within 10 seconds. Do this promptly and smoothly.
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Release Throttle on Stumble: As the engine RPM reaches the target and the CKP relearn process begins, you may hear or feel a slight stumble or misfire. Immediately release the throttle when this occurs.
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Engine Spindown to Idle: Allow the engine to return to its normal idle speed.
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Turn Off Engine: Once the engine has idled, turn the ignition off and wait for 15 seconds.
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Deactivate Scan Tool (Optional): While waiting the 15 seconds, you can click the “Deactivate” button on your Innova 3040 scan tool.
After completing these steps, the CKP relearn procedure should be successfully finished. It’s advisable to verify by checking for any related DTCs and potentially test driving the vehicle to ensure proper engine performance.
