12.4.1.7.1 INSPECT PASSIVE SPEED/TIMING SENSORS Inspect the Passive Speed/Timing Sensors for the following:
a. Inspect for proper mounting.
b. Inspect for loose connections.
c. Inspect for physical and heat damage.
Speed/Timing Sensor close-up With harness disconnected
UPPER SPEED/TIMING
SENSOR
LOWER SPEED/TIMING
SENSOR
d. Disconnect the speed/timing connectors “P44/J44 Upper Speed/Timing Sensor & J20/P20 - Lower Speed/Timing Sensor” and disconnect the harness “pigtail” ends of the sensor harness (2).
Inspect the connectors for the following conditions (Tag the harness connections before disconnecting to ensure proper reconnection of the Speed/Timing Sensor harness connectors).
• Corrosion
• Bent pins
• Missing pins
• Damaged sockets
• Mismating
• Broken wires
12.4.1.7.2 TEST PASSIVE SPEED/TIMING SENSORS To test the Passive Speed/Timing Sensors, proceed as follows:
a. See Caterpillar Manual RENR2227-01 or latest version, Section P – 514 Passive Speed/Timing Sensor for the latest testing instructions.
b. An Over-speed condition is detected by the primary speed/timing sensor, when the engine rpm exceeds 2500 RPM, the Electronic Control Module (ECM) will shut off the electronic unit injectors.
The electronic unit injectors will be shut off until the engine speed drops below 2500 RPM. A diagnostic fault code will be logged into the ECM memory and the “DIAGNOSTIC” lamp will indicate a diagnostic fault code.
12.4.1.7.3 REMOVE PASSIVE SPEED/TIMING SENSORS
REMOVE ALL RINGS, NECKLACES, JEWELERY AND LOOSE CLOTHING.
FAILURE TO DO SO COULD CAUSE SEVERE INJURY OR DEATH.
DO NOT PERFORM THE FOLLOWING TASK WHEN THE GENERATOR SET IS OPERATING. DO NOT TOUCH EXPOSED ELECTRICAL CONNECTION WHEN A SOURCE OF POWER SUCH AS UTILITY POWER OR ANOTHER GENERATOR SET IS CONNECTED TO THE LOAD TERMINALS. DEATH OR INJURY MAY RESULT FROM FAILURE TO OBSERVE THIS WARNING.
WARNING WARNING
WHEN POWER GENERATION EQUIPMENT MUST BE IN OPERATION TO MAKE TESTS AND/OR ADJUSTMENTS, HIGH VOLTAGE AND CURRENT ARE PRESENT.
MAKE SURE THE TESTING EQUIPMENT IS DESIGNED FOR AND CORRECTLY OPERATED FOR THE HIGH VOLTAGE AND CURRENT TESTS. IMPROPER TEST EQUIPMENT MAY FAIL AND PRESENT A HIGH VOLTAGE SHOCK HAZARD TO ITS USER.
CAUTION
CARE MUST BE TAKEN TO ENSURE THAT FLUIDS ARE CONTAINED DURING PERFORMANCE OF INSPECTION, MAINTENANCE, TESTING, ADJUSTING AND REPAIR OF THE PU. BE PREPARED TO COLLECT THE FLUID WITH SUITABLE CONTAINERS BEFORE OPENING ANY COMPARTMENT OR DISASSEMBLY ANY COMPONENT CONTAINING FLUIDS. DISPOSE OF FLUIDS ACCORDING TO LOCAL REGULATIONS AND MANDATES.
To remove the Passive Speed/Timing Sensors, proceed as follows:
a. This maintenance requires that the PU MUST be shutdown, rendered unable to start, cool enough for the maintenance to be performed, and Communication Cable (A) and (B) rerouted to the next PU. This is accomplished by performing the following:
(1) Shutdown the PU in accordance with Section 5.1.6.1 Shutdown Generators.
(2) Isolate the PU from any power plant control system in accordance with Note 1.
(3) Pull to open the PU DC Power Control Breaker.
(4) Push to open both Emergency Stop Switches.
(5) Place both Engine Control Switches (ECS) in the OFF position.
(6) Place a DO NOT OPERATE tag on both generator control panels.
(7) Turn the Battery Bank Parallel Switch to the OFF position.
(8) De-energize both Battery Chargers.
(9) Disconnect the negative and positive cables from both Battery Banks.
(10) Place a DO NOT OPERATE tag on both Battery Banks.
(11) Place all Circuit Breakers in the LOCK OUT position.
(12) Disconnect both 7P1 and 7P2 Connectors located on the inside panel of the PDC.
(13) Close and Lock both generator set control panels.
NOTE 1: When the DC Control Power Circuit Breaker is in the (OFF) position (Pulled – Out), all control power is turned off to the PU. This will cause the HUB to stop functioning. This causes the network to not see the equipment shutdown and all PU’s after it. When pulling major maintenance the (A) (B) Communication Cable must be routed to the next PU in order to reestablish the communication network.
b. Disconnect the wiring harness J44/P44 for the upper speed/timing sensor. Disconnect the wiring harness J20/P20 for the lower speed/timing sensor.
c. Unscrew the retaining clamp bolt that holds each sensor in place, using a wrench, in a counter-clock-wise direction until it comes loose. Pull the sensor free from the engine.
WARNING
12.4.1.7.4 INSTALL PASSIVE SPEED/TIMING SENSORS To install the Passive Speed/Timing Sensors, proceed as follows:
a. This maintenance requires that the PU MUST be shutdown, rendered unable to start, cool enough for the maintenance to be performed, and Communication Cable (A) and (B) rerouted to the next PU. See procedures and warnings in paragraph 12.4.7.4.3.
b. While installing the Passive Speed/Timing Sensors:
• The Top and Bottom Speed/Timing Sensors must be serviced as a pair. The two sensors are not interchangeable and must have correct placement on the engine.
• Lubricate the O-rings with oil.
• Inspect to ensure both sensors have connector face seals inside the connector body. If a seal is damaged or missing, use a 126-5011 replacement seal.
• Inspect to ensure both sensors are fully seated and the seal is in place before tightening the bracket bolt.
• Inspect to ensure the connector is properly latched.
• Inspect to ensure the harness is attached to the engine harness clip.
c. Reinstall speed-timing sensor into place, then the retaining clamp. With a wrench tighten the sensor retaining clamp bolt to18 + 3 Ft-Lbs (24 + 4 Nm).
d. Reinstall the wiring harness J44/P44 for the upper speed/timing sensor. Reinstall the wiring harness J20/P20 for the lower speed/timing sensor.
e. The speed/timing sensors do not need to be Calibrated after they have been installed. See Caterpillar Manual RENR2227-01 or latest version, Section P – 614 Passive Speed/Timing Calibration for the latest instructions. Engine Timing Calibration is only required if the ECM is replaced or if repairs have been made to the engine front drive train.
12.4.1.8 INLET MANIFOLD AIR TEMPERATURE SENSOR
The following maintenance procedures are provided for the Inlet Manifold Air Temperature Sensor:
Inspect Test Remove Install