The Caterpillar Timing Calibration Probe is a critical tool for ensuring the proper functioning of Caterpillar engines after an ECM (Electronic Control Module) replacement. This procedure establishes the precise relationship between the timing wheel and the camshaft position, crucial for optimal engine performance and emissions compliance. This guide provides a detailed walkthrough of the calibration process.
Understanding the Need for Timing Calibration
The ECM relies on accurate timing information to control fuel injection and other critical engine functions. When a new ECM is installed, it lacks the specific timing data for that particular engine. The calibration process, using the Caterpillar timing calibration probe, provides this essential information, enabling the ECM to operate correctly. This calibration is only required after an ECM replacement, not after replacing speed/timing sensors. Performing this procedure unnecessarily will not enhance performance.
Diagnostic Code 22-13: Triggering Calibration
Diagnostic Trouble Code (DTC) 22-13, indicating “Check Timing Sensor Calibration,” specifically triggers the need for this procedure. This code signifies that the ECM has been replaced and requires timing calibration. The engine may run on default timing, resulting in suboptimal performance and potential emissions issues.
Tools and Preparations
Before beginning the calibration, gather the necessary tools and software:
- Caterpillar Electronic Technician (ET): This software is essential for communicating with the ECM and performing the calibration.
- 6V2197 Timing Probe: This specialized probe, also known as the magnetic pickup sensor, detects the timing wheel position.
- 7X1695 Deutsch DT Timing Harness Adapter: This adapter connects the timing probe to the vehicle’s wiring harness.
- 2D6392 O-Ring Seal: Ensures a proper seal for the timing probe.
- Timing Probe Adapter Sleeve: Allows for proper installation of the timing probe.
Step-by-Step Calibration Procedure
1. Install the Timing Adapter Group:
- Turn the ignition OFF and ensure the engine is OFF.
- Locate the timing calibration plug on the left side of the engine, near the flywheel housing and below the ECM. You may need to unbolt the ECM for access.
- Remove the plug and install the Timing Probe Adapter Sleeve.
2. Install the 6V2197 Timing Probe:
- Place the O-Ring Seal on the end of the timing probe, using a small amount of clean engine oil if necessary for easier installation.
- Insert the probe through the adapter sleeve until it contacts the flywheel timing calibration ring.
- Position the O-Ring Seal against the adapter.
- Withdraw the probe 0.04 inches (1.0 mm) and tighten the nut on the adapter sleeve to secure the probe.
- Disconnect Vehicle Speed/TC Calibration Connector J24/P24.
- Connect the timing probe to the Deutsch DT Timing Harness Adapter. Do not connect the adapter to connector P24 yet.
3. Start Engine and Warm to Operating Temperature:
- Start the engine and allow it to warm up until it exits cold mode operation, indicated by the disappearance of “COLD MODE” on the ET status screen and a change in idle speed.
- Check for any active diagnostic codes other than 22-13 and address them before proceeding.
- Set the engine speed to a steady 1100 RPM using cruise control or the throttle. Maintaining a stable RPM between 1000-1200 is crucial for accurate calibration.
4. Connect Caterpillar Electronic Technician (ET):
- Connect ET to the cab data link connector.
- After the engine warms up, select the “Monitor/Calibrate Timing” screen in ET.
- Connect the Deutsch DT Adapter Harness to the Vehicle Speed/TC Connector P24.
5. Calibrate the Speed/Timing Sensors:
- Press the “space” key in ET to initiate calibration. The first press displays the “Timing Error” bar; the second initiates calibration. Wait for ET to indicate “CALIBRATED.”
- If “COULD NOT CALIBRATE” appears, double-check connections and tool operation. Incorrect crank and cam gear assembly can also prevent calibration.
- Once calibrated, do not exit the “Monitor/Calibrate Timing” screen until the timing probe is disconnected from connector P24.
6. Disconnect Timing Probe and Exit “Monitor/Calibrate Timing” Screen:
- Disconnect the Timing Probe from connector P24.
- Exit the “Monitor/Calibrate Timing” screen in ET. The engine RPM may drop to programmed low idle; this is normal.
By following these steps and utilizing the Caterpillar timing calibration probe correctly, you ensure the accurate timing essential for optimal engine performance, fuel efficiency, and emissions compliance after an ECM replacement.
