
RENR5622 157
Troubleshooting Section
Calibration Procedures
i02415146
Engine Sp eed/Timing Sen sor -
Calibrate
SMCS Code: 1912-524
System Operation Description:
Use this procedure if the diagnostic code in Table
43 is active.
Table 43
Diagnostic Codes Table
Description
Conditions which Generate this Code System Response
MID 0036 - CID 0091 - FMI 08 Throttle
Position signal abnormal
The engine’s speed/timing sensor
needs calibration.
Thecodeisactiveonly.
The engine speed/timing sensor is calibrated
through a two-step process. A new timing reference
is calculated first. The reference is based on
the signals from the transducer and the engine
speed/timing sensor. Next, the new timing reference
is programmed into the permanent memory of the
engine’s Electronic Control Module (ECM).
The engine speed/timing sensor provides engine
information to the ECM. The ECM powers the engine
speed/timing sensor with 12.5 ± 1.0 VDC. The sensor
senses the tooth pattern on the timing reference gear
that is attached to the left camshaft. As the timing
gear rotates past the engine speed/timing sensor, a
signal is generated in the sensor. This signal is sent
to the ECM. The ECM uses this signal in order to
calculate the engine position and the engine speed.
A loss of the engine speed/timing signal causes the
ECM to stop sending power to the fuel injectors.
Calibration of the timing is required only after the
following circumstances:
•
The ECM has been replaced.
•
The speed/timing sensor has been replaced.
•
The timing gear and/or the rear gear train have
been adjusted.
•
The timing gear and/or the rear gear train have
been replaced.
Test Step 1. Check for an “ACTIVE”
Diagnostic Code.
A. Turn the keyswitch to the OFF position.
B. Connect Caterpillar Electronic Technician (ET) to
the service tool connector.
C. Remove the timing calibration plug from the
flywheel housing.
D. Examine the flywheel through the timing
calibration hole. Ensure that the probe is not
inserted into the timing pin hole. If necessary,
rotate the engine.
E. Install the 6V-3093 Transducer Adapter into the
hole for the timing calibration at the flywheel.
F. Insert the 6V-2197 Tr ansducer through the
6V-3093 Transducer Adapter. Insert the
transducer until contact is made with the surface
of the flywheel. Move the transducer 0.9 mm
(0.04 inch) away from the flywheel.
NOTICE
Do not install the timing calibration probe over the tim-
ing pin hole in the flywheel or damage will result.
G. Tighten the nut on the 6V-3093 Transducer
Adapter.
H. Connect the 7X-1695 Cable As between the
transducer and the timing calibration connector
P26.
I. Turn the keyswitch to the START position.
J. Start the engine. Allow the engine to exit cold
mode operation.
K. Monitor the diagnostic codes on Cat ET. Check
and record any diagnostic codes.