Usage:
Certain parameters that affect 3176 Engine operations may be changed using Electronic Service Tools. The parameters are stored in the ECM, NOT the Personality Module. Any parameter can be read, but passwords protect parameters from unauthorized changes.
The parameters fall into two categories: System Configuration Parameters and Customer Specified Parameters. System Configuration Parameters can be changed only with the correct factory passwords (using an ECAP) and Customer Parameters can be changed only with the correct customer passwords (using an ECAP or DDT). See the following section on Passwords for more details on how to get and use passwords.
For details on how to read and change parameters using an ECAP and the appropriate Service Program Module, refer to Special Instruction Form No. SEHS8742, Using The 8T8697 Electronic Control Analyzer Programmer (ECAP), and Special Instruction Form No. SEHS8886, Using the NEXG4507 3176 Functions Service Program Module. For the DDT, refer to Operating Manual Form No. SEHS8808, Using The NEXG4509 3176 Electronic Unit Injector (EUI) Engine Service Program Module, and Operating Manual Form No. SEHS9076, Using The 7X6400 Digital Diagnostic Tool (DDT) Group.
Connecting ECAP Or DDT To 3176 System:
The Electronic Control Analyzer and Programmer (ECAP) and Digital Diagnostic Tool (DDT) use 12 volt DC power from the vehicle battery. This permits operation either beside the engine or in the cab of the truck during a road test.
Use the following procedures to connect the service tool to the engine:
A. Turn key OFF.
B. The ECAP or DDT is connected to the 3176 System at the 9-Pin, Power/Data Link Connector (J8/P8), or at the optional 9-Pin Dash Data Link Connector (J12). Install the 8T5275 'T' Harness on one of the connectors (only one side of the 'T' harness connector cable is used on J12).
C. Connect the other end of the 'T' Harness to the ECAP/DDT.
D. Turn key ON to begin testing. The ECAP/DDT will operate with the engine running, or on truck battery power only. If the ECAP/DDT does not communicate with the 3176 System, refer to, P-120: ECAP/DDT Will Not Communicate With 3176 System.
System Configuration Parameters
System Configuration Parameters are those that affect emissions or horsepower of the engine. They are programmed at the factory and would normally never need to be changed through the life of the engine. Correct values for these parameters are stamped on the Engine Information Plate located on the valve cover. Factory Passwords are required to change these parameters.
Full Load Setting:
Number representing fuel system adjustments made at the factory to "fine tune" the fuel system. Correct value for this parameter is stamped on the Engine Information Plate for each engine.
Full Torque Setting:
Similar to Full Load Setting.
Personality Module Code:
Code which prevents use of wrong Personality Module for this engine. Each horsepower family and emission certification has a different code associated with it. This code (stored in ECM) MUST match that in the Personality Module or a Diagnostic Code 56 (Check Customer Or System Parameters) will be generated and the engine will only idle. When rerating the engine or installing a new ECM, programming this code to 0 will prompt the ECM to read and match its stored code to the Personality Module. Note that this code DOES NOT need to be programmed when a Personality Module is replaced, as long as the new module is of the same family. If the module is of a different family, the engine is in effect being rerated-pistons, injectors, turbocharger, etc. may also need to be changed and the Engine Information Plate should be changed to reflect the new engine rating.
Engine Serial Number:
Should be programmed to match the engine serial number stamped on the Engine Information Plate and the Engine Serial Number Plate.
NOTE: A new ECM is delivered with the engine serial number programmed to 0XX00000.
Customer Specified Parameters
Customer Specified Parameters allow a customer to restrict how a driver operates the vehicle. Some parameters may affect engine operation in ways that the uninformed driver does not expect. These parameters may lead to power and/or performance complaints, even when the engine is operating to specifications.
For detailed instructions on how to program the 3176 Diesel Truck Engine for optimum performance and fuel economy, refer to Form LEKT8587, Developing Parameters For The 3176 Diesel Truck Engine.
NOTE: If the NEXG4512 Customer Parameter Configuration Aid, Service Program Module (Optional Electronic Service Tool) is installed in an ECAP equipped with the 8C9700 Rechargeable Portable Printer, a list of Customer Specified Parameters can be read from the ECM and printed out. A split chart can also be plotted showing gear shift points.
Customer parameters may be changed repeatedly as a customer changes his operation or as new drivers are assigned to a truck. Customer Passwords are required to change these parameters.
The following is a brief description of the Customer Specified Parameters. Along with each, are the minimum and maximum values for the parameter and the default value. If a feature is not used, the parameter should be programmed to the default value.
Vehicle Speed Parameters
Vehicle Speed Calibration:
Used by the ECM to scale the Vehicle Speed Signal reading into miles per hour. It is programmed in pulses per mile. For more information, refer to P-304: Vehicle Speed Calibration, in this manual.
Vehicle Speed Limit:
Top vehicle speed the ECM will permit with load. The ECM will shut fuel off above this speed.
Minimum ... 30 mph
Maximum ... 127 mph
Default ... 127 mph
Engine RPM At Vehicle Speed Limit (VSL):
Highest rpm that engine will turn at programmed Vehicle Speed Limit. The ECM will limit to this rpm only when it sees no vehicle speed signal and the engine is loaded.
Minimum ... 1300 rpm
Maximum ... 3000 rpm
Default ... 3000 rpm
NOTE: When this parameter is programmed to 3,000 rpm, Diagnostic Codes 31 and 36 are disabled and VSL can be exceeded by disconnecting the Vehicle Speed Sensor.
Cruise Control Parameters
Low Cruise Limit:
Lowest speed (mph) at which cruise can be engaged.
Minimum ... 15 mph
Maximum ... 127 mph
Default ... 127 mph
High Cruise Limit:
Highest speed (mph) at which cruise can be engaged.
Minimum ... 30 mph
Maximum ... 127 mph
Default ... 127 mph
Engine Retarder Mode:
Defines operation of "Retarder Enable" signal while in cruise mode. Allowable options are: COAST or LATCH. When programmed to COAST, the retarder is enabled only while the service brakes are being applied. When programmed to LATCH, the retarder stays enabled after the service brakes are released (a quick press of the brake pedal latches the retarder ON). Refer to P-227: Retarder Enable Signal Test for more detail on operation of the Retarder Enable Signal Test
PTO Parameters
PTO Mode Speed Limit:
Maximum mph for PTO mode.
Minimum ... 1 mph
Maximum ... 15 mph
Default ... 15 mph
PTO Mode RPM Limit:
Maximum engine rpm in PTO mode.
Minimum ... 600 rpm
Maximum ... 3000 rpm
Default ... 3000 rpm
Progressive Shifting Parameters
Low Gears #1 RPM Limit:
Engine rpm limit below "Low Gear #1 Turn Off Speed". The engine will pause at this rpm, then allow slow acceleration up to Top Engine Limit. This is to encourage the driver to shift to the next highest gear.
Minimum ... 1100 rpm
Maximum ... 3000 rpm
Default ... 3000 rpm
Low Gears #1 Turn Off:
Vehicle Speed where "Low Gear #1 RPM Limit" turns OFF. This must be matched with "Low Gear #1 RPM Limit" to the specific drive train for best performance.
Minimum ... 3 mph
Maximum ... 30 mph
Default ... 30 mph
Low Gears #2 RPM Limit:
Similar to "Low Gear #1 RPM Limit". Typically programmed to slightly higher rpm.
Minimum ... 1100 rpm
Maximum ... 3000 rpm
Default ... 3000 rpm
Low Gears #2 Turn Off:
Similar to "Low Gear #1 Turn Off". Typically programmed to slightly higher vehicle speed.
Minimum ... 5 mph
Maximum ... 50 mph
Default ... 50 mph
Hi Gear RPM Limit:
Engine RPM Limit when vehicle speed is above "Hi Gear Turn On Speed." This is a "hard" limit; the 3176 System will not power the engine above this limit. This is to encourage the driver to shift into overdrive or top gear.
Minimum ... 1300 rpm
Maximum ... 3000 rpm
Default ... 3000 rpm
Hi Gear Turn On Speed:
Vehicle Speed where "Hi Gear RPM Limit" turns ON. This must be matched to the specific drive train for best performance.
Minimum ... 30 mph
Maximum ... 127 mph
Default ... 127 mph
Engine Parameters
Rating Number:
Number of rating within the horsepower family. The personality module defines the horsepower family (such as 325 hp). This number defines which rating is used (such as 325 hp at 1900 rpm or 325 hp at 2100 rpm) within the family.
Top Engine Limit (TEL):
Maximum engine rpm when the engine is under load. The engine will still achieve rated rpm under no load.
Minimum ... Map (Rating) Dependent
Maximum ... Rated rpm + 20 rpm
Default ... Rated rpm + 20 rpm
Low Idle RPM:
Minimum engine rpm.
Minimum ... 600 rpm
Maximum ... 750 rpm
Default ... 700 rpm
Idle Shutdown Time:
Time (in minutes) that engine will idle before shutting down (between 3 and 60 minutes). Engine will only shut down if the ECM sees no engine load, no vehicle speed, the parking brake is set and there has been no change in the status of the service brakes and clutch. If this parameter is programmed to 0, the feature is disabled. Refer to P-230: Idle Shutdown Timer Test for more detail on operation of the idle shutdown timer.
Minimum ... 3 min.
Maximum ... 60 min.
Default ... 0 min.
Vehicle ID:
Identification of vehicle assigned by customer. Used only for customer reference; not used by the ECM.
Factory Passwords
Factory Passwords are required to perform any one of these four functions:
1. Program a new ECM.
When an ECM is replaced, the System Configuration Parameters must be programmed into the new ECM. These parameters are protected by Factory Passwords.
2. Rerate the engine to another engine family.
This requires changing the Personality Module Code, which is protected by Factory Passwords.
3. Read Customer Passwords.
If the owner forgets his Customer Passwords, he will not be able to program Customer Specified Parameters. Using factory passwords, one can read Customer Passwords, then use those Customer Passwords to program Customer Specified Parameters.
4. Clear certain diagnostic codes.
Only Diagnostic Code 35 (Engine Overspeed) requires Factory Passwords to clear once it is LOGGED. Clearing certain other codes requires Customer Passwords. The majority of LOGGED diagnostic codes require no passwords to clear.
Factory Passwords are controlled by Caterpillar and may only be obtained by authorized Caterpillar Dealers.
NOTE: Since factory passwords contain alphabetic characters, only the ECAP may perform these functions
To obtain factory passwords, proceed as if you already had the password. At some point, if factory passwords are truly needed, the ECAP will request factory passwords and will provide most of the information required to obtain the password on the ECAP screen.
Customer Passwords
Customer Passwords are required to change ANY Customer Parameter. Customer Specified Parameters are those that affect cruise control, vehicle speed limits, progressive shifting, horsepower rating within a family and PTO operation. See the previous section on "Customer Specified Parameters" for more detail on which parameters are customer programmable.
Either the ECAP or DDT can be used to change Customer Parameters. However, if a customer uses alphabetic characters in his password, only the ECAP can enter the Customer Passwords to change Customer Specified Parameters.
To obtain Customer Passwords, contact the owner of the vehicle. If the owner has forgotten his passwords, customer passwords may be read using an ECAP by following these steps:
1. If the customer has lost or forgotten his passwords, use the ECAP to access "Read/Change System Configuration Parameters", then "Read Customer Passwords".
2. When the Factory Passwords screen appears, record the information listed on the "3176 Factory Passwords Worksheet" (in this section).
NOTE: Leave the ECAP on this screen.
3. Obtain the Factory Passwords. The information recorded on the worksheet must be provided to the factory to obtain Factory Passwords. A permanent record of the inquiry will be recorded at the factory.
4. From the Factory Passwords screen, enter the Factory Passwords.
5. When the "Read Customer Passwords" screen appears, record the Customer Passwords. The Customer Passwords may then be used to change Customer Specified Parameters.
Programming New Electronic Control Modules
The Electronic Control Module or ECM, is the heart of the Electronic Control System used on 3176 Diesel Truck Engines. You should be aware that the ECM has no moving parts, has a very high reliability rating and can be time consuming to replace. Most failures occur in wiring & connectors, sensors or fuel injectors. Be sure to follow the troubleshooting procedures outlined in this guide. Be certain that you will be fixing the customer's problem before replacing the ECM.
The parameters stored in the ECM to be replaced, must be read on an ECAP or DDT and recorded. The Transducer Module and the Personality Module must be removed from the old unit and installed on the new one. After the new ECM is installed on the engine, it must be programmed and the boost pressure sensor and the speed/timing sensor must be recalibrated.
The following procedure is a summary of the basic steps necessary to program a replacement ECM.
Step 1:
Use a copy of the "3176 Customer Specified Parameters Worksheet" on the next page, to record the Customer Specified Parameters from the ECM being replaced.
A. Obtain and record the Customer Passwords. If the customer (owner) has lost or forgotten his passwords, refer to the "Customer Passwords" element in this section to access and record the passwords.
B. Use the ECAP to access "Customer Specified Parameter" from the ECM being replaced.
C. Record the "Customer Specified Parameters" listed on the worksheet.
Step 2:
Replace the faulty ECM.
Step 3:
Use a copy of the "3176 Factory Passwords Worksheet" (on the next page), to obtain the Factory Passwords.
- * Engine Serial Number
- * Full Load Setting
- * Full Torque Setting
- * Full Load Setting
A. Record the following information from the Engine Information Plate:
B. Record the engine mileage from the vehicle odometer.
C. Connect the ECAP. When first powered up, the ECAP will display its serial number while going through its self tests. Read and record the ECAP Serial Number.
D. Use the ECAP to access "Read/Change System Configuration Parameters" from the new ECM.
- * ECM Serial Number
- * Engine Serial Number (should read 0XX00000).
- * Total Tattletales
- * Engine Serial Number (should read 0XX00000).
E. When the Factory Passwords screen appears, record the following information:
NOTE: Leave the ECAP on this screen.
F. Obtain the Factory Passwords. The information recorded above must be provided.
Step 4:
Program the 3176 System Configuration Parameters
A. From the Factory Passwords screen, enter the Factory Passwords.
B. When the "Read/Change System Configuration Parameters" screen appears, enter the: Full Load Setting, Full Torque Setting And Engine Serial Number recorded on the worksheet. Program the Personality Module Code to 0 before leaving this screen.
Step 5:
Program the Customer Specified Parameters.
NOTE: If the Customer Specified Parameters are entered before the System Configuration Parameters, the Total Tattletales will change. It will then be necessary to obtain another set of Factory Passwords to access "Read/Change System Configuration Parameters".
A. Use the ECAP to access "Read/Change Customer Specified Parameters".
B. Enter the Customer Specified Parameters recorded in Step 1 and the original Customer Passwords.
Step 6:
Calibrate Sensors:
A. Use the ECAP to access "Calibrate Sensors" screen and calibrate the Boost Pressure Sensor (refer to P-302: Boost Pressure Sensor Calibration).
B. Use the ECAP to access "Calibrate Sensors" screen and calibrate the Speed/Timing Sensor (refer to P-301: Engine Speed/Timing Sensor Calibration).
Programming New Personality Modules
Since all programmable parameters are stored in the ECM, there is no need to program new personality modules. As long as the new personality module is the same horsepower and emissions family as the old module, no pass words are needed.