SETSCREW-SQUARE HEAD 4B3604 - Caterpillar

Use this procedure if the diagnostic code in Table 1 is active.
Table 1
J1939 Code and Description CDL Code and Description Comments
637-11
Engine Timing Sensor : Other Failure Mode 261-11
Engine Timing Offset fault The wiring to the sensors has the wrong polarity.
637-13
Engine Timing Sensor : Out of Calibration 261-13
Engine Timing Calibration : Calibration Required A timing calibration is required for a new engine, replacing an Electronic Control Module (ECM) that fails to communicate or following work on the front gear train, the camshaft, or the crankshaft. If a 261-11 or 637-11 diagnostic code is active, verify that the wiring is installed correctly to the engine speed/timing sensors.The ECM can calibrate the mechanical differences between the Top Center (TC) of the flywheel and the TC of the timing gear on the camshaft. A transducer signals the TC of the flywheel to the ECM when a notch on a counterweight passes by the transducer. The engine speed/timing sensor signals the TC of the timing gear to the ECM. Any offset between the TC of the flywheel and the TC of the timing gear is stored into the memory of the ECM.Note: A timing calibration will not increase the available engine power.Table 2 lists the special tools that are required in order to perform this procedure.
Table 2
Required Special Tools
Part Number Description
7X-1171 Transducer Adapter
6V-2197 Transducer
7X-1695 Cable as
170-3519 Harness (1)
(1) This item is not required if the engine harness has a connector for timing calibration.
Illustration 1 g03048383
(A) Timing mark
(B) Idler gear
Table 3
Troubleshooting Test Steps Values Results
Step 1 applies to C15 and C18 engines only.
1. Check the Gear Train Timing
The camshaft gear will be off a half tooth if the engine is timed when Cylinder # 6 is at Top Dead Center (TDC). The engine MUST be timed when Cylinder #1 is at TDC. The engine MUST be timed when Cylinder #1 is at Top Dead Center (TDC). Do NOT time the engine with Cylinder #6 at TDC as the camshaft gear will be off a half tooth.
Note: Remove the rocker arms before rotating the engine to prevent piston/valve damage from occurring.
A. If the engine is at TDC for cylinder 6, remove cam idler gear (B) and rotate the crankshaft 360 degrees and repin the flywheel.
B. Install idler gear (B).
C. Check timing mark (A).
D. Rotate the engine by hand 360° to ensure that the engine rotates freely. If the engine does not rotate freely, the engine is not timed correctly. Remove the front housing and check all timing marks. Refer to Testing and Adjusting, "Gear Group (Front) - Time" for the correct procedure.
E. Connect to Cat ET and clear the DTC.
F. Start the engine.
Diagnostic code
Result: After starting the engine the code is still present.
Proceed to Test Step 2.
Result: After starting the engine the code did not return.
Return the unit to service.
Table 4
Crankshaft Rotation
Engine Model Number of Degrees Direction of Rotation
C9.3 85 Normal Rotation
C13 75 Normal Rotation
C15 60 Opposite Normal Rotation
C18 30 Opposite Normal Rotation
Table 5
Location of the Timing Calibration Port
Engine Model Crankshaft Counterweight Engine