3512C and 3516C Engines Caterpillar


Engine Speed/Timing Sensor

Usage:

3516C 9F4
System Operation Description:

Use this procedure to troubleshoot the electrical system if a problem is suspected with the engine speed/timing sensor or if one of the diagnostic codes in Table 1 is active.

Table 1
Diagnostic Codes Table 
Description  Conditions which Generate this Code  System Response 
190-2 Engine Speed Sensor erratic, intermittent, or incorrect  The engine speed signal cannot be detected. The timing gear pattern returns within one second before being lost and the battery voltage is greater than 9 VDC for the last two seconds. The code will be active and logged if the Electronic Control Module (ECM) detects an incorrect signal for one second. The battery voltage is greater than 9 VDC for the last two seconds.  The engine speed is set to zero rpm.
The code is logged only if the engine has been running for three seconds. 
190-3 Engine Speed Sensor voltage above normal  A wire on the engine speed/timing sensor is disconnected and/or broken. There is a short circuit to the +Battery terminal.  The engine speed is set to zero rpm.
The code is logged. 
190-8 Engine Speed Sensor abnormal frequency, pulse width, or period  The engine speed is greater than zero rpm and the pattern from the timing ring is incorrect for five seconds.  The engine speed is set to zero rpm.
The code is active.
The code is logged if the pattern from the timing ring returns for five seconds. 

The ECM provides the engine speed/timing sensor with 12.5 ± 1 VDC. The engine speed/timing sensor provides a pulse signal to the ECM. The signal is created as the timing reference gear rotates past the pickup of the engine speed/timing sensor. The timing reference gear is mounted on the rear of the left camshaft. A unique tooth pattern on the timing reference gear allows the ECM to determine the crankshaft position, rotation, and rpm.

The engine speed/timing sensor generates a pulse signal to the ECM as each tooth passes the sensor. The ECM counts the pulses in order to determine the engine rpm. The ECM memorizes the pattern of the pulses. The ECM compares that pattern to a standard pattern in order to determine the crankshaft position. The ECM uses this information to determine the position of the No. 1 cylinder. The ECM then triggers each unit injector to fire in the correct firing order and at the correct time. The actual timing and duration of each injection is determined by the ECM. The ECM uses engine rpm and engine load to determine the timing and duration of injection. The loss of the signal from the engine speed/timing sensor generates an alert on the Caterpillar Electronic Technician (ET). The loss of the signal from the engine speed/timing sensor triggers the termination of the signals to the fuel injectors by the ECM.

Note: If the engine timing gear is installed backward, the diagnostic code 190-08 will be generated. If this code is active, the ECM will not fire the injectors.



Illustration 1g01241934
Typical schematic


Illustration 2g01216172
P1 ECM connector
(P1-5) Digital return
(P1-33) Engine speed/timing signal
(P1-40) Engine timing calibration -
(P1-41) Engine timing calibration +
(P1-43) +12.5 V supply


Illustration 3g01218411
Typical left side view
(1) Engine speed/timing sensor


Illustration 4g01234146
Location of ECM connectors

Test Step 1. Inspect Electrical Connectors and Wiring

  1. Remove electrical power from the ECM.

  2. Thoroughly inspect the ECM connectors J1/P1 and J2/P2. Inspect all of the other connectors for the circuit. Refer to Troubleshooting, "Inspecting Electrical Connectors" for details.

  3. Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector that are associated with the circuit.

  4. Check the ECM connector (allen head screw) for the proper torque. Refer to Troubleshooting, "Inspecting Electrical Connectors" for details.

  5. Check the harness and the wiring for abrasion and for pinch points.

Expected Result:

All connectors, pins, and sockets are completely coupled and/or inserted. The harness and wiring are free of corrosion, of abrasion or of pinch points.

Results:

  • OK - The harness and connectors appear to be OK. Proceed to Test Step 2.

  • Not OK - There is a problem with the connectors and/or wiring.

    Repair: Repair the connectors or wiring and/or replace the connectors or wiring. Ensure that all of the seals are properly in place and ensure that the connectors are completely coupled.

    Verify that the repair eliminates the problem.

    STOP

Test Step 2. Check for an "ACTIVE" or "LOGGED"Diagnostic Code

  1. Connect Caterpillar Electronic Technician (ET) to the service tool connector.

  2. Restore electrical power to the ECM.

  3. Check the diagnostic codes on Cat ET.

Expected Result:

No diagnostic codes are active or logged repeatedly.

Results:

  • OK - A diagnostic code for the engine speed/timing sensor is not active or logged repeatedly.

    Repair: The problem is no longer present. If the problem is intermittent, refer to Troubleshooting, "Inspecting Electrical Connectors".

    STOP

  • Not OK - A diagnostic code for the engine speed/timing sensor is active or logged repeatedly. Proceed to Test Step 3.

Test Step 3. Check the Supply Voltage to the Sensor

  1. Disconnect the connector for the engine speed/timing sensor.

  2. Restore electrical power to the ECM.

  3. Measure the voltage between terminal A and terminal B at the sensor connector.

Expected Result:

The supply voltage is 12.5 ± 1 VDC.

Results:

  • OK - The supply voltage is 12.5 ± 1 VDC. Proceed to Test Step 4.

  • Not OK - The supply voltage is not 12.5 ± 1 VDC. Proceed to Test Step 6.

Test Step 4. Check the Signal Voltage at the Sensor

  1. Remove electrical power from the ECM.

  2. Remove the wire from terminal C of the sensor connector.

  3. Restore electrical power to the ECM.

  4. Measure the voltage between the sensor's signal wire and terminal B of the sensor connector. Crank the engine and measure the voltage between the sensor signal wire and terminal B.

  5. Remove electrical power from the ECM.

  6. Reconnect the signal wire.

Expected Result:

The voltage measures less than 3 VDC or more than 9 VDC when the ECM is powered and the engine is not cranking. While the engine is cranking, the voltage is between 2 VDC and 7 VDC.

Note: The voltage output is determined by the presence or the absence of a tooth on the timing gear.

Results:

  • OK - The engine speed/timing sensor is producing the correct output signal. Proceed to Test Step 5.

  • Not OK - The engine speed/timing sensor is not producing the correct output signal.

    Repair: Replace the engine speed/timing sensor. Calibrate the sensor. Perform the calibration procedure Troubleshooting, "Engine Speed/Timing Sensor - Calibrate".

    STOP

Test Step 5. Check the Signal Voltage at the ECM

  1. Remove electrical power from the ECM.

  2. Disconnect ECM connector J1/P1.

  3. Remove the signal wire 999-BK(Black) from ECM connector P1-33.

  4. Reconnect ECM connector J1/P1.

  5. Restore electrical power to the ECM.

  6. Measure the signal voltage between the signal wire and wire D998-BK(Black) in ECM connector P1-5.

  7. Crank the engine and measure the signal voltage between the signal wire and engine ground.

  8. Remove electrical power from the ECM.

  9. Replace all wires. Reconnect ECM connector J1/P1.

Expected Result:

The voltage measures less than 3 VDC or more than 9 VDC when the ECM is powered and the engine is not cranking. While the engine is cranking, the voltage is between 2 VDC and 7 VDC.

Note: The voltage signal is generated by the presence or the absence of a tooth on the timing gear.

Results:

  • OK - The correct voltage appears at ECM connector P1 but the ECM is not reading the signal.

    Repair: Replace the ECM. Refer to the diagnostic procedure Troubleshooting, "Replacing the ECM".

    STOP

  • Not OK - There is a problem in the engine speed/timing circuit.

    Repair: The problem is between the ECM and the engine speed/timing sensor. Repair the connectors and/or wiring or replace the connectors and/or wiring.

    STOP

Test Step 6. Check the Supply Voltage for the Engine Speed/Timing Sensor at the ECM

  1. Remove electrical power from the ECM.

  2. Disconnect ECM connector J1/P1.

  3. Remove the supply wire 996-BK(Black) from ECM connector P1-43. Install a wire jumper into the socket for P1-43.

  4. Reconnect ECM connector J1/P1.

  5. Restore electrical power to the ECM.

  6. Measure the supply voltage between wire D998-BK(Black) in ECM connector P1-5 and the wire jumper in P1-43.

  7. Remove electrical power from the ECM.

  8. Remove the wire jumper and replace all wires. Reconnect ECM connector J1/P1.

Expected Result:

The supply voltage is 12.5 ± 1 VDC.

Results:

  • OK - The supply voltage is 12.5 ± 1 VDC. There is an open circuit or a short circuit between the ECM and the connector for the engine speed/timing sensor.

    Repair: Repair the connectors and/or wiring or replace the connectors and/or wiring.

    STOP

  • Not OK - The supply voltage is not 12.5 ± 1 VDC. The supply voltage is incorrect.

    Repair: Replace the ECM. Refer to Troubleshooting, "Replacing the ECM".

    STOP

Caterpillar Information System:

3512C and 3516C Engines Engine Control Switch (ECS)
C15 and C18 Generator Set Engines Crankshaft Position Sensor - Remove and Install
C15 and C18 Engines for Caterpillar Built Machines E539 High Intake Manifold Air Temperature
24M Motor Grader Machine Systems Alarm (Action)
3512C and 3516C Engines Emergency Stop Switch (Remote)
C9 Industrial Engines Reference Material
C15 and C18 Generator Set Engines Camshaft Position Sensor - Remove and Install
C15 and C18 Generator Set Engines Fuel Pressure Sensor - Remove and Install
C15 and C18 Generator Set Engines Fuel Temperature Sensor - Remove and Install
3512C and 3516C Engines Electrical Power Supply
3508C, 3512C and 3516C Marine Engines Valve Mechanism Cover Base - Remove and Install
3508C, 3512C and 3516C Marine Engines Cylinder Head - Remove
Electronic Injector Height Adjustment and Setting{1251, 1290} Electronic Injector Height Adjustment and Setting{1251, 1290}
3508C, 3512C and 3516C Marine Engines Accessory Drive (Front) - Remove - Engine Oil Pump and Water Pump
C15 and C18 Generator Set Engines E197 High Engine Oil Temperature
3512C and 3516C Engines Prelubrication System
3512 Industrial Engine Engine Design
C15 and C18 Generator Set Engines E085 Engine Shutdown Overridden
Procedure for Adding Filtration Capability to Solvent Stands {0680} Procedure for Adding Filtration Capability to Solvent Stands {0680}
3508C, 3512C and 3516C Marine Engines Accessory Drive (Front) - Install - Engine Oil Pump and Water Pump
UPS 120, UPS 150, UPS 250 and UPS 300 Uninterruptible Power Supplies Pager Configuration
C15 and C18 Generator Set Engines Event Codes
C9 On-highway Engine Water Temperature Regulator Housing
C7 Marine Engines Electronic Control Module - Remove and Install
Back to top
The names Caterpillar, John Deere, JD, JCB, Hyundai or any other original equipment manufacturers are registered trademarks of the respective original equipment manufacturers. All names, descriptions, numbers and symbols are used for reference purposes only.
CH-Part.com is in no way associated with any of the manufacturers we have listed. All manufacturer's names and descriptions are for reference only.