3406E, C-10, C-12, C-15, C-16 & C-18 Electronic Troubleshooting
Electronic Controls
The engine’s electronic system consists of the Engine Control Module (ECM), the engine sensors and the vehicle interface. The ECM is the computer. The personality module is the software for the computer. The personality module contains the operating maps. The operating maps define the following characteristics of the engine:
• Horsepower
• Torque curves
• RPM
• Other characteristics
Engine Governor
The Electronic Controls on the engine serves as the engine governor.
The Electronic Controls determine the timing and the amount of fuel that is delivered to the cylinders.
These decisions are based on the actual conditions and the desired conditions at any given time.
The governor uses the accelerator pedal position sensor to determine the desired engine speed. The governor compares the desired engine speed to the actual engine speed. The actual engine speed is determined through the primary engine speed/timing sensor. If the desired engine speed is greater than the actual engine speed, the governor injects more fuel in order to increase engine speed.
The desired engine speed is typically determined by one of the following conditions:
• The position of the accelerator pedal
• The desired vehicle speed in cruise control
• The desired engine rpm in PTO control
Timing Considerations
Once the governor has determined the amount of fuel that is required, the governor must determine the timing of the fuel injection. Fuel injection timing is determined by the ECM after considering input from the following components:
• Coolant Temperature Sensor
• Intake Manifold Air Temperature Sensor
• Atmospheric Pressure Sensor
• Boost Pressure Sensor
At start-up, the ECM determines the top center position of the number 1 cylinder from the signal from the secondary engine speed/timing sensor. After start-up, the ECM determines the top center position of the number 1 cylinder from the primary engine speed/timing sensor. The ECM decides when fuel injection should occur relative to the top center position and the ECM provides the signal to the injector at the desired time. The ECM adjusts timing for the best engine performance, the best fuel economy and the best control of white smoke. Actual timing cannot be viewed with the Caterpillar Electronic Technician (Cat ET), and desired timing cannot be viewed with Cat ET.
Fuel Injection
The ECM controls the amount of fuel that is injected by varying the signals to the injectors. The injectors will pump fuel only if the injector solenoid is energized. The ECM sends a high voltage signal to the solenoid. This high voltage signal energizes the solenoid. By controlling the timing and the duration of the high voltage signal, the ECM can control injection timing and the ECM can control the amount of fuel that is injected.
The personality module inside the ECM sets certain limits on the amount of fuel that can be injected. The FRC Limit (Fuel) is based on the boost pressure. The FRC Limit (Fuel) is used to control the air/fuel ratio for control of emissions. When the ECM senses a higher boost pressure, the ECM increases the FRC Limit (Fuel). A higher boost pressure indicates that there is more air in the cylinder. The ECM allows more fuel into the cylinder when the ECM increases the FRC Limit (Fuel).
The Rated Fuel Limit is a limit that is based on the power rating of the engine and engine rpm. The Rated Fuel Limit is similar to the rack stops and the torque spring on a mechanically governed engine. The Rated Fuel Limit provides the power curves and the torque curves for a specific engine family and a specific engine rating. All of these limits are determined at the factory. These limits are in the Personality Module and these limits cannot be changed.
Cold Mode
The ECM will set cold mode when the coolant temperature is below 18 °C (64 °F).
Cold mode is activated five seconds after the start of the engine. During cold mode, low idle speed will be increased to 800 rpm. After 60 seconds, the engine speed is reduced to 600 rpm. Engine power will be limited until cold mode is deactivated. Cold mode will be deactivated when the coolant temperature reaches 18 °C (64 °F).
Customer Parameters And Engine Speed Governing
A unique feature with electronic engines is customer specified parameters. These parameters allow the vehicle owner to fine tune the ECM for engine operation. Fine tuning the ECM for engine operation allows the vehicle owner to accommodate the typical usage of the vehicle and the power train of the vehicle.
Many of the customer parameters provide additional restrictions on the actions that will be performed by the ECM in response to the driver’s input. For example, the “PTO Top Engine Limit” is an engine rpm limit. The “PTO Top Engine Limit” is an engine rpm limit that is used by the ECM as a cutoff for the fuel. The ECM will not fuel the injectors above this rpm.
Some parameters are intended to notify the driver of potential engine damage (“Engine Monitoring Parameters”). Some parameters enhance fuel economy (“Vehicle Speed Parameters”, “Cruise Control Parameters”, “Engine/Gear Parameters” and “Smart Idle Parameters”). Other parameters are used to enhance the engine installation into the vehicle. Other parameters are also used to provide engine operating information to the truck engine owner.
Diode Added To Prevent Damage To Time Delay Relay
All Marine, Industrial, Generator Set Engines Except 3600 Family Of Engines
Reference: Engine News; November, 1985; Page 5, “Engine Shuts Down Immediately After Start-up”. Engine News; February 22, 1984; Page 9, “Engine Will Not Restart Immediately After It Has Been Shutdown”.
Description of Change: The above engines have a 4W8471 Relay. This is a 70 second time delay relay (TDR) to make sure the engine stops completely when it is shutdown. A diode has been added to the circuit connected to the TDR to prevent damage to the TDR from high voltage spikes.
Adaptable To: The 5N4988 Diode Assembly can be adapted to only the affected engines previously modified in the field to make it possible to override the 70 second TDR. This field modification has allowed voltage spikes to damage the TDR. Current production does contain a redesigned override feature that prevents damage to the TDR from voltage spikes. The control panel circuits on the earlier engines could have been modified in the field in one of two ways, depending on the design of the circuit.
For circuits modified according to the first Reference Article (read Solution B), use Illustration 1. On these engines, the junction box jumper between terminals 27 and 28 has been removed, and terminal 27 has been connected to the output side of the electric starter magnetic switch (solenoid). Simply connect the new diode between 27 and 28 as shown.
Illustration 1. Diode added to engines previously modified according to the November 1985 Engine News.
For circuits modified according to the second Reference Article, use Illustration 2. Disconnect B- wire at 3 Neg terminal on the TDR. Connect the new diode to the B- wire and to the 3 Neg terminal as shown.
Illustration 2. Diode added to engines previously modified according to the February 22, 1984 Engine News.
Electrical System Damage From High Voltage
All Products With Direct Electric Starting
Reference: Service Magazine; May 28, 1990; Page 4; “Jump Starting Procedures.” Service Magazine; May 4, 1987; Page 10; “Alternator/Generator Output Test on the Engine.”
Electrical components may suffer damage from high electrical system voltage. Damage identified by parts returned to the factory includes arc.burn spots in small switches and connectors. Electronic controls show damage to printed circuit boards. Electronic components show damage from arcing and burning. These damages are possible only from extremely high voltages.
The cause of component damage is generally one of two possibilities:
1. Incorrect jump starting procedure, where a stalled engine is jumped by a source with voltage higher than the system voltage of the stalled engine. See the first Reference Article.
2. When the alternator voltage regulator is shorted, causing full (rated) charging current, AND an open circuit or loose connection exists in the charging circuit.
The regulator adjusts alternator output by varying field current to maintain correct system voltage. Regulators have, mainly, two failure modes: open or shorted. When open, there is no field current and no alternator output. If shorted, field current is maximum causing maximum rated, uncontrolled, output current, provided the engine is running at or above about 75% of rated engine speed.
Batteries serve two main functions in ANY electrical system:
1. Provide energy for cranking the engine.
2. Act as an accumulator to provide a “smoothing” effect for electrical system voltage variations.
Alternators serve two main functions in ANY electrical system:
1. To recharge batteries after an engine startup.
2. To supply ALL electrical system requirements after the engine is running.
If all connections are tight, full alternator output will, first, cause battery damage. Batteries become the “load” for a runaway alternator. They absorb alternator current that is above what is required for normal machine operation. This high current causes battery damage from excessive: electrolyte temperatures, plate warping, and water loss. As the electrolyte level (water) drops, the chance of battery explosion increases and system voltage will also increase out of control. The result is damage to other electrical system components like relays, lighting and electronic controls.
Full alternator output with loose or poor connections in the charging circuit (even with batteries in good condition) can cause immediate high voltage damage to electrical system components. Loose or poor connections, such as at the battery terminals, can cause short periods of an “open circuit,” which has the same result as batteries with low electrolyte. Opening the disconnect during an overcharging condition also has the same effect as a loose connection.
The following are clues to high charging system voltage due to voltage regulator failure:
1. More than one lighting component blackened or dead. One or more electronic controls dead.
2. Electrolyte level low in ALL cells of ALL batteries.
3. If engine is operational, charging voltage measures over 29.0 volts (or over 15.0 volts for 12V systems).
The following are clues to incorrect jump starting:
1. More than one lighting component blackened or dead. One or more electronic controls functioning incorrectly.
2. One or more batteries exploded. Electrolyte level in undamaged cells appears normal.
3. If engine is operational, charging voltage appears normal. If alternator was damaged by reverse hookup of jump source, the most likely failure would be low or no alternator output.
3306 Cylinder – Final Engine Assembly
Use a 1P2991 Tap to remove burrs from each head bolt hole. Thoroughly clean each hole to remove excess fluid and debris which would affect final torque values.
Lightly coat the head bolt threads, washers and bottom of bolt heads with 6V4876 Molykote Paste Lubricant. Use of this friction reducing paste will significantly improve the load on the head gasket. Do not use oil.
Install the head gasket dry. Remove excess oil/grease from the top of the liner flanges, spacer plate and bottom of the cylinder head with solvent or preferably 8T9011 Component Cleaner.
1. Clean the surfaces of the cylinder head and the cylinder block that make contact with each other. Make sure the surfaces are clean and dry. Install a new dry gasket (2) on the cylinder block.
2. Fasten a hoist to the cylinder head (1) and put it in position on the cylinder block.
3. Put 6V4876 Molykote Paste Lubricant on all the head bolts and rocker shaft bolts.
NOTE: Do not tighten bolts at this time.
4. Loosen the adjusting screws on the rocker arms for valve clearance. This will prevent a bent valve or push rod at installation.
5. Install push rods (4) and rocker shaft assembly (3). Install the bolts and washers that hold the rocker shaft in place.
6. Tighten the bolts as follows:
(1) Large bolts. Put 6V4876 Molycoat on bolt threads and between washer and underside of bolt heads. Tighten bolts in the following step sequence.
a. Tighten bolts from 1 through 26 in number sequence to a torque of … 155 N·m (115 lb ft).
b. Tighten bolts from 1 through 26 in number sequence to a torque of … 250 ± 17 N·m (185 ± 13 lb ft).
c. Tighten bolts from 1 through 26 in number sequence again to a torque of … 250 ± 17 N·m (185 ± 13 lb ft).
d. Tighten bolts A through G in letter sequence (hand tighten only) to a torque of 43 ± 7 N·m (32 ± 5 lb ft).
6. Make an adjustment until the intake valve lash is 0.38 mm (.015 in) and the exhaust valve lash is 0.64 mm (.025 in). Tighten the locknuts (5) for the adjusting screws to a torque of 29 ± 7 N·m (21 ± 5 lb ft).
7. Connect tube assembly (6) and install the bolts to fasten clips (7).
3306 Cylinder – Head Bolts
nspect head bolts for reusability. Replace the head bolts that have surface damage (pitting or erosion) on the shank that cannot be polished smooth.
The high stress areas on a bolt are:
1. The first exposed thread root on the joint side of the nut or tapped hole.
2. The first thread root after the shank.
3. The underhead fillet.
Damage in these areas can lead to bolt failure.
Corrosion on bolt shank. Do Not Reuse.
Corrosion on bolt shank. Do Not Reuse.
Combustion gas leakage can lead to corrosion on the bolt shank. If this corrosion damage cannot be removed with emery paper or wet-dry sand paper, replace the bolt. Any remaining irregular surfaces would create unnecessary stress raisers and ultimately weaken the bolt.
3306 Cylinder Liner Projection
NOTE: This procedure alleviates the need for the “H” bar to hold down liners during projection measurements.
Illustration 1.
Liner projection components
1. Bolt.
2. Hard washer.
3. Washer.
4. Fabric washer.
5. Spacer plate.
6. Spacer plate gasket.
7. Cylinder liner.
8. Block.
Install clean liners or cylinder packs (without the filler band or the rubber seals), spacer plate gasket and clean spacer plate.
Install bolts and washers, as indicated previously, in the holes indicated with an X. Install all bolts or the six bolts around the liner. Tighten the bolts to a torque of 95 N·m (70 lb ft).
Use the 8T0455 Liner Projection Tool Group to measure liner projection at positions indicated with and A, B, C and D. Record measurements for each cylinder. Add the four readings for each cylinder and divide by four to find the average.
If the liner projections are out of specification, try rotating the liner or install the liner in another bore to see if the measurements improve.
Do not exceed the maximum liner projection of 0.175 mm (0.0069 in). Excessive liner projection will contribute to liner flange cracking.
With the proper liner projection, mark the liners in the proper position and set them aside.
When the engine is ready for final assembly, the o-ring seals, cylinder block and upper filler band must be lubricated before installation.
If the lower o-rings are black in color, apply liquid soap on the lower o-ring seals and the cylinder block. Use clean engine oil on the upper filler band.
If the lower o-rings are brown in color, apply engine oil on the lower o-ring seals, the cylinder block and the upper filler band.
NOTE: Apply liquid soap and/or clean engine oil immediately before assembly. If applied too early, the filler bands may swell and be pinched under the liners during installation.
3306 Cylinder Block – Counterbore For Liner Seat Inserts
Counterbore only the block liner seats that exhibit measurable erosion of 0.025 mm (0.001 in) or greater. Generally, liner seat erosion resulting from a head gasket failure require counterboring only one or two cylinder liner seats. Use only stainless steel inserts. The part numbers are 9L5855, 9L5856, 9L5857 and 9L5858.
Protected crankshaft journal.
When machining work is done on a cylinder block, special precautions are required to protect other engine components from contamination. Protect the crankshaft rod journals adjacent to the repair by covering with paper towels and taping. Cover the lifter bore area with paper towels or foam inserts. Tape or coat with heavy grease the oil supply dowel to prevent chip entry.
Installation of counterbore tool.
Install counterboring tool and tighten the hold down bolts to a torque of 68 N·m (50 lb ft). A counterboring tool, equipped with a dealer fabricated handle for continuous rotation of the tool, provides a smoother cut than a tool equipped with a “Tee” style handle. Continuous rotation of the tool reduces tool chatter caused by start-stop rotation. Machine a maximum of 0.10 mm (.004 in) for any one dial setting.
Depth gauge.
Use depth gauge to measure progress when nearing the depth needed to install the thinnest insert. Reduce machine depth to .025 mm (0.001 in) per cut until reaching the final depth. Measure to verify actual insert thickness and install insert so that it is flush with the top of the block within 0.013 mm (.0005 in).
NOTE: The bore in the block for the insert should be 144.051 ± 0.025 mm (5.671 ± .001 in).
Left: A good counterbore. Right: Chatter marks must be cleaned up before assembly.
Counterbore machining.
If counterboring to the depth of the thinnest insert does not clean up 100 percent of the erosion/crack damage, machine to the depth of the next insert.
NOTE: At the time of installation, the stainless steel inserts are installed dry (WITHOUT the use of sealants).
1. The design of insert (1) and the size of the counterbore give the insert a slip (loose) fit in the cylinder block. The outer diameter of the counterbore is 144.051 ± 0.025 mm (5.671 ± .001 in). If the counterbore has been cut correctly, the top of the insert will be even or within 0.0127 mm (0.0005 in) of the top surface (A) of the cylinder block to give the necessary projection for the cylinder liner. Location (B) shows the liner seat area that must clean up 100 percent before it is permissible to install an insert in the counterbore. The radius (C), 0.64 ± 0.13 mm (0.025 ± 0.005 in), is determined by the cutting tool.
2. There is a plus or minus tolerance for the thickness of the insert and for the depth of the counterbore. When inserts are installed in a cylinder block, there must be no more than 0.05 mm (0.002 in) difference in height between the inserts of any two counterbores that are next to each other. It is necessary then, to measure the depth of each counterbore and install an insert of the correct thickness to give the 0.05 mm (0.002 in) specification. The insert thickness should be measured prior to installation to determine the plus or minus tolerance.
Counterbore deburring.
When machining is complete, deburr both edges of the counterbore with emery paper or #400 wet-dry sandpaper. Use a wet-dry vacuum to remove cuttings from cylinder bores, water jacket and head bolt holes. Remove plastic bore plugs, foam inserts, paper towels, tape and all other protective covers. If necessary, run threaded tap down head bolt holes to remove burrs and thoroughly clean out head bolt holes. Wash down cylinder block with solvent or use pressure air to ensure block/crankshaft/lifter bore cleanliness. Install inserts dry (no sealant) with chamfer facing down.
3306 Cylinder Block – Top Deck Repair
Cylinder block top deck cleaning.
Clean the cylinder block top deck completely with wire brush or “Scotchbrite” pad. Use caution when cleaning around the liner bores with rotary abrasive pads. The liner seat can be damaged if pad is not held parallel with the block surface. This damage and its reduced seating area may cause a head joint failure shortly after engine operation has begun.
Removing burrs from top deck.
After cleaning, use a flat file to dress the top deck to remove burrs and highlight the original factory milling marks.
Milling pattern marks.
Carefully inspect each liner seat area for signs of measurable erosion. Determine measurable erosion with an 8T0455 Liner Projection Tool Group. Measurable erosion generally will destroy the milling mark pattern and exhibit a rough, pebbly surface. If erosion directly under the liner flange measures .025 mm (.001 in) deep or more with the depth gauge, record these measurements in the Service Report.
Measurable erosion under liner flange is permissible when the eroded area is not more than .025 mm (.001 in) deep. Multiple areas of erosion are also permissible if depth does not exceed .025 mm (.001 in) deep. These small areas of erosion under the liner flange are acceptable. The liner flange is designed with sufficient rigidity to span those areas without affecting sealability of the head gasket. This erosion or fretting damage is acceptable if it does not affect liner projection.
Milling marks evident, no visible or measurable erosion, liner seat areas with dark stains. Do Not Counterbore.
Milling marks evident, no visible or measurable erosion, liner seat areas with dark stains. Do Not Counterbore.
Milling marks evident, no visible or measurable erosion, liner seat areas with dark stains. Do Not Counterbore.
Milling marks evident, no visible or measurable erosion, liner seat areas. Do Not Counterbore.
Casting damage extends more than half way across width of liner seat. Counterbore to restore liner seat flatness.
Erosion and milling mark pattern measures less than 0.025 mm (0.001 in) deep. Do Not Counterbore.
Erosion and milling mark pattern measures less than 0.025 mm (0.001 in) deep. Do Not Counterbore.
Measurable erosion outside the immediate liner seat. Do Not Counterbore.
Measurable erosion occuring outside the immediate liner seat area is permissible. This erosion does not affect the stability of the liner nor the sealing ability of the head gasket. This erosion will not clean up by counterboring.
Erosion under the water ferrules and outside the liner seat area.
Erosion under the water ferrules is permissible. This erosion can be filled with 5P3321 Epoxy, a compound of liquid metal fillers or Belzona “Ceramic R”.
NOTE: Machining the top deck of the block for this type of erosion around the water ferrule is NOT required.
Pebbly block surface in liner seat.
Measurable erosion of .0890 mm (0.0035 in) deep.
Rough pebbly block surface in liner seat area must be measured. Erosion measuring more than .025 mm (0.001 in) deep must be removed by counterboring. Repair this damage by counterboring the block deck and installing the thinnest possible stainless steel insert.
3306 Cylinder Liner – Flange Thickness
Use a 6V7059 Micrometer to measure the thickness of the flange.
Measure the thickness of the flange with a 6V7059 Micrometer. Use the liner again only if it is acceptable according to the specifications in the chart below.
Liner with significant erosion/corrosion in filler band area, under liner flange and in fillet radius (crack could be hidden by glass beading or by improper cleaning) – Do Not Use Again
Liner with nick on the bottom of flange – Do Not Use Again
Damage to the fire dam. Use Again only if the damage is not extended completely across the fire dam and any burrs or sharp edges are removed.
Damage in the gasket surface area. Do Not Use Again.
Nick in the vertical flange edge. Use Again after any sharp edges or high areas are removed with a file.
Chip in the seal edge of the flange. Do Not Use Again.
Rough, pebbly surface extending in a random pattern. Do Not Use Again.
Pits and fretting under the liner flange. Large pits or groups of pits are not acceptable, especially in the radius. Do Not Use Again.
Fretting is acceptable when it is circumferential and does not prevent the liner from sealing. Measure flange thickness. Use Again.
3306 Cylinder Liner – Inspect Flanges
Extended operation after a head gasket failure or filler band leakage can allow erosion or corrosion on the liner flange to cylinder block joint(s). Excessive amounts of erosion/corrosion damage can affect the sealing capability of the head to block joint if not corrected. In order to thoroughly inspect this joint, the cylinder packs must be removed.
Do not measure liner projection before cylinder pack removal unless necessary to verify the workmanship of a previous repair.
Remove all cylinder packs from the engine using the 8T0812 puller or equivalent. Use care when removing the packs from the block to guard against inadvertent damage to the liner seat by the connecting rod/bolts. Remove the filler bands and clean the liner flange/seat area with a hand or rotary wire brush to allow for careful visual inspection. Do not use glass beads as this process will disguise any erosion or flange cracks.
Evidence of minor fretting/dark stains or discoloration is acceptable when it is circumferential and does not prevent the liner from sealing. Groups or patches of pits/erosion occurring in random patterns under the liner flange are not acceptable; do not reuse the liner. This type of extensive damage normally occurs adjacent to similar erosion on the cylinder block.
Measure the liner flange thickness in four places, 90° apart or in eroded areas.