CT660 CX31 and CX31 HT On Highway Truck Power Train Electronic Control System Caterpillar

Transmission - Calibrate

Usage:

CX31 D9F

Note: Transmissions with prefix PTT 1-up, PTW 1-up, EBW 1000 1-up are all factory calibrated. A Hands Free Calibration (HFC) is still needed for field service in case there is a need to replace components on the transmission after a failure.

This procedure is used in order to optimize the quality of shifts. The procedure must be performed under the following conditions:

After replacing the engine horsepower rating.
Perform the procedure after replacing the ECU or servicing the ECU.
Perform the procedure after exchanging the ECU from one machine to another machine.
·After replacing or servicing any of the transmission clutches, lock-up clutch, or oil system (seals, pumps, ECPC valves, oil cooler, main relief valve).

Note: The calibration procedure will require the vehicle to be driven. Shift quality will improve throughout the calibration process and stabilize to a consistent level as calibration is completed

Show/hide table




Illustration 1	g02509696
Screen capture of ET Transmission Configuration Screen

Reset the calibration process using Caterpillar Electronic Technician (Cat ET).
- Open Cat ET and connect to transmission
- Confirm J1939 connection
- Click "Configuration" on the menu bar
- Select "Vehicle Configuration Parameters" from the options on the left side
- Click "Transmission Calibration Configuration" from the drop-down list
- Program the calibration to "All Clutches" (Illustration 1)
- Cycle power to the ECU by turning off the key-switch, and then start the vehicle.
Using Caterpillar Electronic Technician (ET) version 2009B and newer is recommended when connected to a TCM with the latest software installed. ET version 2009B and newer can monitor the calibration procedure using the "Clutch Calibration" group from within the Status screen. The status screen will show the status of each individual clutch, along with error codes, transmission gear, engine speed, driveshaft speed, and transmission oil temperature. A snapshot of this screen is shown below (Illustration 2 & 3). When a clutch has completed calibration, its value will read "Complete".
Show/hide table

Illustration 2 g02509716
Bring the transmission oil temperature to 60° C (140° F). The calibration process will not begin until the oil temperature reaches 60° C (140° F).
Verify that the transmission fluid is at the correct level with the vehicle on a level surface, engine at low idle, and transmission fluid at operating temperature, 60° C (140° F). The fluid level can be checked using the dipstick, or using the internal oil level sensor. The internal oil level sensor is accessed by simultaneously pressing the up & down arrows on the shift pad. The shift pad display will then count down to 00 and then display one of the following codes:
- OL-OK (Oil level is OK)
- OL-HI-## (Oil level is High by ## quarts)
- OL-LO-## (Oil level is Low by ## quarts)
If the count down timer does not begin, the problem is due to one of the following error displays:
- OL-EL (Engine speed is too Low)
- OL-EH (Engine speed is too High)
- OL-XN (Transmission is not in Neutral)
- OL-TL (oil Temperature is too Low)
- OL-TH (oil Temperature is too High)
- OL-VS (Vehicle Speed is not zero)
Shifts Out of Neutral (Garage Shifts),- With the parking brake RELEASED and the service brake APPLIED, shift the transmission from NEUTRAL to DRIVE to NEUTRAL. Then shift the transmission from NEUTRAL to REVERSE to NEUTRAL. Repeat these shifts until there is no noticeable change in shift quality or until the values in the table below are removed from the Clutch Calibration Status Screen Values.
Within the ET Clutch Calibration Status Screen, the following values will be removed when this procedure is complete:
Show/hide table
Table 1
Description CX31 Value

Clutch #1 Calibration Status N-D

Clutch #3 Calibration Status N-R

Clutch #4 Calibration Status n/a

Full Throttle (FT) Upshifts- With both service and parking brake RELEASED, begin driving the vehicle. From a stop, accelerate the vehicle using 100% throttle and allow the vehicle to shift from first up to fifth for CX31. Repeat these shifts until there is no noticeable change in shift quality or until the values in the table below are no longer shown in the Clutch Calibration Status Screen.

Within the ET Clutch Calibration Status Screen, the following values will be removed when this procedure is complete:

Show/hide table

Table 2
Description	CX31 Value
Clutch #1 Calibration Status	n/a
Clutch #2 Calibration Status	3-4 FT
Clutch #3 Calibration Status	2-3 FT
Clutch #4 Calibration Status	1-2 FT
Clutch #5 Calibration Status	n/a
Lockup Clutch Calibration Status	2C-2L

7. Coasting (CST) Downshifts – Accelerate the vehicle to fifth gear for CX31. Allow the vehicle to coast and downshift into first gear with zero throttle input. Minimize any braking during these downshifts. Repeat these shifts until there is no noticeable change in shift quality or until the values in the table below are no longer shown in the Clutch Calibration Status Screen.

Within the ET Clutch Calibration Status Screen, the following values will be removed when this procedure is complete:

Show/hide table

Table 3
Description	CX31 Value
Clutch #1 Calibration Status	5-4 CST
Clutch #3 Calibration Status	4-3 CST
Clutch #4 Calibration Status	3-2 CST
Clutch #5 Calibration Status	2-1 CST
Clutch #6 Calibration Status	n/a

8. 2-1 Tip-In CX31 – Take the vehicle to second gear and maintain a steady throttle position with engine speed at 1200-1300 rpm. The transmission will abruptly downshift to first gear. Repeat this step until the 2-1 no longer occurs with engine speed at 1200-1300 rpm or until the value in the table below are no longer shown in the Clutch Calibration Status Screen.
Within the ET Clutch Calibration Status Screen, the following values will be removed when this procedure is complete:
Show/hide table
Table 4
Description CX31 Value

Clutch #5 Calibration Status 2-1 Tip-in
5-4 Tip-In CX31– 5-4 Tip-in shifts are achieved by accelerating the vehicle to fifth gear. Allow the vehicle to coast down to the 5-4 shift point with zero throttle position ( usually 1200-1400 rpm for engines with 1200 rpm peak torque speed or 1300-1600 rpm for engines with 1440 peak torque speed). Quickly push the throttle pedal to the floor. The transmission should downshift to fourth gear. Repeat these shifts until there is no noticeable change in shift quality or until the value in the table below are no longer shown in the Clutch Calibration Status Screen.
Within the ET Clutch Calibration Status Screen, the following values will be removed when this procedure is complete:
Show/hide table
Table 5
Description CX31 Value

Clutch #1 Calibration Status 5-4 Tip-in

10. Calibration Complete – Upon completion of the clutch calibration, the following values will be displayed in the ET Clutch Calibration Status Screen:

Show/hide table

Table 6
Description	CX31 Value
Clutch #1 Calibration Status	Complete
Clutch #2 Calibration Status	Complete
Clutch #3 Calibration Status	Complete
Clutch #4 Calibration Status	Complete
Clutch #5 Calibration Status	Complete
Clutch #6 Calibration Status	Complete
Lockup Clutch Calibration Status	Complete

If the operator then goes back to the ET Transmission Configuration Screen, the value for "Transmission Calibration Configuration" should now read "Disabled" (Illustration 4).

Show/hide table




Illustration 3	g02509876

Calibration Error Codes that can show up during the calibration procedure:

Unsteady Throttle - Shift disqualified if throttle position varies by more that ±20% during clutch fill.
Oil Temp Out of Range - Transmission oil temperature below 60° C (140° F) or above 100° C (212° F).
Torque Below Upshift Requirements - Calculated torque below limit at start of upshift. Limit set to 200 N-m for CX31.
Governed Engine Speed - Shift disqualified if engine speed exceeds the vehicle governed engine speed during the shift.
Service Brake Applied During Shift - Shift disqualified if the service brake is applied during the 2 to 1 coasting downshift.
Retarding Shift - Shift disqualified if engine retarder is active during the shift.