Application and Instruction Guide for the Driveline PTO on CX28, CX31, and CX35 On-Highway Transmissions{1408, 3030, 3108} Caterpillar

On-Highway Transmission:

CX28 (S/N: TBB1-UP; T3X1-UP)

CX31 (S/N: D9F1-UP; D9R1-UP; EBW1-UP; B3X1-UP)

CX35 (S/N: W3X1-UP)

Introduction

This special instruction covers the application of a driveline that has a power take-off (PTO) for the CX28, CX31, and CX35 transmission for on-highway trucks. The information includes the electronic inputs and outputs that are required. Also, the information includes the electronic inputs and outputs that are optional. The instruction is for a chassis that has been assembled and all wiring for roading has been installed. This includes all the batteries, the interface for the engine, the parking brake, the service brake and the shifter. If additional information regarding basic installation and the application of the Series CX transmission is necessary, that information of the electronic requirements and options for the Series CX transmission may be found in Special Instruction, REHS2884, "Application and Installation Guide (Electrical) for the CX28, CX31, and CX35 On-Highway Transmissions".

The driveline (PTO) for Series CX transmissions was designed exclusively for pumping applications on an apparatus with a split driveline that is used to fight fires. The programmable parameters for support and control of the PTO are standard on Series CX transmissions. No special hardware or software is required. Required information for wires, pins, and connectors is listed at the end of this document.

Safety Procedures

Welding on a Vehicle that is Equipped with a Series CX Transmission

Note: Before welding on a vehicle that is equipped with an electronic transmission control, the following steps must be performed.

1. Place the ignition switch in the OFF position.

2. Disconnect the negative battery cable from the battery. If the vehicle is equipped with a battery disconnect switch, open the switch.

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NOTICE
DO NOT use electrical components in order to ground the welder. Do not use the ECU or sensors or any other electronic component in order to ground the welder. Clamp the ground cable for the welder to the component that will be welded. Place that clamp as close as possible to the weld. This will reduce the possibility of damage to the bearings of the drive train, hydraulic components, ground straps, and other components of the vehicle.

3. Clamp the ground cable of the welder to the component that will be welded. Place the clamp as close as possible to the weld.

4. Protect any wiring harnesses from welding debris and spatter. Use proper welding procedures in order to weld the materials.

ReferenceRefer to Special Instruction, REHS1841, "General Welding Procedures" for all welding.

Overview of Basic Operation

Illustration 1	g01374253
Transmission driveline with a split shaft (PTO) (1) Pump (2) Transmission driveline with a split shaft (PTO)

1. Drive the vehicle to the site.

2. Set the parking brake and select Neutral.

3. Engage the mode for the pump. The mode for the pump disengages the rear axle and the mode for the pump engages the pump.

4. Select Drive. The Series CX transmission selects the programmed gear for pumping.

5. Accelerate the engine to pumping speed.

6. Pump the water.

7. The operation for pumping is complete.

8. Return engine to LOW IDLE

9. Select NEUTRAL of the Series CX Transmission.

10. Engage the mode for roading. The mode for roading disengages the pump and the mode for roading engages the rear axle.

11. Release the parking brake and drive from the site.

Chassis Interface for the Transmission Driveline of the Power Take Off

Required Chassis Interface

• Request switch for the pump mode input

• Positive pump mode engagement switch input

• The Gear driver output enables the Ok to pump lamp indicator and is used as one of the interlocks for the OK to pump lamp.

Required Chassis Interface Description

Pump Mode Request Switch Input

The pump mode request switch input tells the Series CX transmission that the vehicle operator has requested the change from propelling the vehicle to pumping water.

Positive Pump Mode Engagement Switch Input

The positive pump mode engagement switch input tells the Series CX transmission that there has been a successful transition from propel mode into pump mode.

Gear Driver Output

The Gear Driver Output is used to indicate that the transmission has attained the programmed gear for operation of the driveline power take off (DPTO). This output is used as a lamp driver and one of the interlocks in the circuit for OK to Pump.

Optional DPTO Chassis Interface Connections

Parking Brake Switch

A parking brake should be considered for safe stationary operation of the pump.

Secondary Shift Selector

A secondary shift selector could be included in the vehicle pump station design. A secondary shifter will allow for out of the cab operation, of the Pump Mode.

Typical Wiring Diagram for the PTO

Illustration 2	g01374259

Optional Selector for Secondary Shift on the Transmission

Illustration 3	g01374515

The option of including a secondary transmission shift selector, allows for transmission shift control from the Pump Control Station. Programming of the Shifter number 2 Configuration parameter to "J1939" and the installation of a switch input at "J2: 35" is required for the remote operation of the shifter. This switch would be interlocked with other circuits in order to prevent the switch input of a "J2: 35" from being activated during operations that do not use the pump mode.

Programming the Parameter to Support Operational Requirements

The following table lists the driveline PTO programmable parameters which are needed to support the operation of the driveline PTO.

Table 1

Programmable Parameter	Range Options	Explanation
Driveline PTO Mode Enabled Gear Configuration	Not Configured Gear 1, Gear 2, Gear 3, Gear 4, Gear 5, Gear 6, Gear 7, and Gear 8	Determines the forward gear the transmission will shift into when drive is selected and the transmission is in the DPTO mode.
Driveline PTO Minimum Engine Speed for Torque Converter Lockup	Low Idle to High Idle (engine)	Determines the required rpm of the engine for the torque converter to engage.
Driveline PTO Minimum Engine Speed for Latching	Low Idle to High Idle (engine)	Determines the engine rpm for the DPTO mode to disengage.
Driveline PTO Latching Enabled Status	Enabled, Disabled	Determines if the DPTO mode will latch and stay engaged until the engine rpm drops below the programmed minimum speed.
Desired Status of the Inertia Brake	Enabled, Disabled	Determines if the transmission will automatically engage the output shaft brake in order to allow for easier pump mode or roading mode engagement
Gear Indicator X Enabled Status (Where X is the same gear as programmed in Driveline PTO Mode Enabled Gear Configuration	Enabled, Disabled	Enabled Gear Configuration Informs the operator and the Pump Mode interlock system, that the transmission has shifted into the programmed gear for the pumping operation.
Shifter number 2 Configuration	"J1939", Not Installed, (PWM is Not Supported)	Programming this parameter to "J1939" will enable the Remote shifter. This also requires a switch input.

Programming Notes

The Switch to Battery 1 option will not be available to be used with any other feature when the "Driveline PTO Mode Enabled Gear Configuration" parameter is programmed to a gear. If the Switch to Battery 1 input is already programmed to another feature, attempted programming of the "Driveline PTO Mode Enabled Gear Configuration" parameter will be rejected.

Choosing the Correct Gear for Pumping Operations

The "Driveline PTO Mode Enabled Gear Configuration" customer parameter is used to select the gear for driveline PTO operation. The correct gear for the desired pump speed will be based on the gear ratio of the transmission. The typical pump operation requires a ratio of 1 to 1 (engine speed to shaft speed of the transmission output). For the CX28 and CX31 transmissions, Gear 4 is for pump operation. For CX35 transmissions, Gear 6 is for pump operation.

Table 2

Gear Ratios
CX28	Gear	Ratio
	Reverse	3.97
	1F	3.76
	2F	1.96
	3F	1.35
	4F	1.00
	5F	0.78
	6F	0.65
CX31	Reverse	3.97
	1F	4.40
	2F	2.33
	3F	1.53
	4F	1.00
	5F	0.72
	6F	0.61
CX35	Reverse	4.46
	1F	5.73
	2F	3.57
	3F	2.70
	4F	1.95
	5F	1.43
	6F	1.00
	7F	0.74
	8F	0.63

Torque Converter Lockup Programming

The "Driveline PTO Minimum Engine Speed for Torque Converter Lockup" customer parameter is used to establish the engine speed that the torque converter's lockup clutch will engage. Engagement of the lock up clutch will increase the efficiency of the overall vehicle system. Cooling requirements of the transmission are also reduced. The transmission, once the initial DPTO range is attained, will engage the torque converter lockup clutch approximately one second after the programmed speed is exceeded. When engaged, the torque converter lockup clutch will not disengage until the engine speed is 200 rpm less than the programmed speed, or if the engine falls below low idle speed. A typical value for this parameter is 1000 rpm. If required, the torque converter lockup clutch may remain disengaged in order to provide a compliant element in the DPTO system. To prevent the torque converter from engaging, the "Driveline PTO Minimum Engine Speed for Torque Converter Lockup" customer parameter will be programmed to a value beyond the normal driveline PTO operating range.

DPTO Latch Programming

Some applications require the DPTO mode to be disengaged solely based on the engine speed value. This provides a robust system, which once the DPTO is engaged, will continue to function during inadvertent shift selector requests or faults in the DPTO switch inputs. The "Driveline PTO Latching Enabled Status" customer parameter is provided in order to enable or disable the Latch. The "Driveline PTO Minimum Engine Speed for Latching" customer parameter is used to set the engine speed that will cause the transmission to latch the gear for pumping.

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NOTICE
Once latched, the transmission will remain in gear until the engine speed is reduced to 200 rpm below the "Driveline PTO Minimum Engine Speed for Latching" programmed speed. The transmission will ignore selecting Neutral from the shift selector, changing the status of the Driveline PTO switch input, the Driveline Engaged switch input, and releasing the parking brake.

Programming of the Inertia Brake

With the transmission in Neutral, the output shaft can continue to rotate after the pumping action is completed and Neutral is selected. With the "Driveline PTO Inertia Brake Enabled Status" programmable parameter programmed to Enabled, the transmission's internal clutches will act as an inertia brake to stop the output shaft's rotation. This will aid in shifting back into Road mode.

Gear Driver Output Programming

The "Gear Indicator Enabled Status" must be programmed to same gear as the "Driveline PTO Mode Enabled Gear Configuration" programming. This output will be enabled when the operator has selected "D" on the gearshift selector and the transmission has shifted into the programmed gear for driveline PTO operation. This output will be included in the interlock system for the "OK to Pump" indication circuit.

Pump Shift Assist

Caterpillar Series CX transmissions have a feature called Pump Shift Assist that is designed to help in the transition between Road Mode and Pump Mode.

In the event that the positive pump engagement circuit (J2: 54) does not close within one second after the DPTO pump mode request circuit (J2:14) is closed, the CaterpillarSeries CXtransmissions will temporarily apply a small amount of torque to the transmission output shaft. This torque will cause the transmission output shaft to rotate. The rotation will help to engage the internal driveline PTO components. This will assist the driveline PTO device in completing the shift from road to pump mode. If the positive pump engagement circuit does not close within 30 seconds, this torque will be removed and the Pump Shift Assist feature will be deactivated until the DPTO pump request circuit is opened and then closed again.

Typical operation

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Illustration 4	g01717114
Gearshift Selector Display

1. The Operator Selects Neutral and engages the Parking Brake.
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   Table 3

   Step	Gear Selected	Shift Selector Display	Vehicle Switches			Pump Mode Request Lamp	Positive Pump Engage Lamp	OK to Pump Lamp	Inertia Brake
   			Pump Mode Request switch J2:14	Positive Pump Engage J2:54	Gear Driver Output J2:11
   1	N	NN	Off	Off	Off	Off	Off		Off

2. The Operator should Select the Pump Mode.

   The operator is to move the selector from Road Mode to Pump Mode.

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   Table 4

   Step	Gear Selected	Gearshift Selector Display	Vehicle Switches			Pump Mode Request Lamp	Positive Pump Engage Lamp	OK to Pump Lamp	Inertia Brake
   			Pump Mode Request switch J2:14	Positive Pump Engage J2:54	Gear Driver Output J2:11
   2	N	NN	On	Off	Off	On	Off	Off	Off

3. At the mechanical completion of the split shaft PTO system shift into pump mode from road mode the positive pump engagement switch should be enabled.
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   Table 5

   Step	Gear Selected	Shift Selector Display	Vehicle Switches			Pump Mode Request Lamp	Positive Pump Engage Lamp	OK to Pump Lamp	Inertia Brake
   			Pump Mode Request switch J2:14	Positive Pump Engage J2:54	Gear Driver Output J2:11
   3	N	NN	On	On	Off	On	On	Off	Off

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Illustration 5	g01717573

4. Select forward gear for pumping operation.

   Once the mechanical shift into pump mode has been accomplished, the operator can now request the programmed forward gear for pumping.

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   Table 6

   Step	Gear Selected	Shift Selector Display	Vehicle Switches			Pump Mode Request Lamp	Positive Pump Engage Lamp	OK to Pump Lamp	Inertia Brake
   			Pump Mode Request switch J2:14	Positive Pump Engage J2:54	Gear Driver Output J2:11
   4	D	4N	On	On	Off	On	On	Off	Off

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Illustration 6	g01717576

5. After the transmission has completed the shift into the gear for pump mode, the programmed gear driver output circuit will be enabled.
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   Table 7

   Step	Gear Selected	Shift Selector Display	Vehicle Switches			Pump Mode Request Lamp	Positive Pump Engage Lamp	OK to Pump Lamp	Inertia Brake
   			Pump Mode Request switch J2:14	Positive Pump Engage J2:54	Gear Driver Output J2:11
   5	D	44	On	On	On	On	On	On	Off

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Illustration 7	g01717594

6. When the left digit is flashing, the operator is required to once again select Neutral on the gearshift selector and then ensure that the vehicle is prepared to enter pump mode before shifting back into drive.

   Note: The left digit on the shift selector will flash if conditions are not met for DPTO operation or if a switch input inadvertently is opened during pumping operation. If the pump request switch input is closed but other switch input conditions are not met for the pumping operation, the transmission will remain in Neutral and the left digit will flash. If the transmission is in the pump mode operation and a switch input is inadvertently opened, the transmission will shift into Neutral and the left digit will flash.

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   Table 8

   Step	Gear Selected	Shift Selector Display	Vehicle Switches			Pump Mode Request Lamp	Positive Pump Engage Lamp	OK to Pump Lamp	Inertia Brake
   			Pump Mode Request switch J2:14	Positive Pump Engage J2:54	Gear Driver Output J2:11
   6	D	4N	On	Off	Off	On	Off	Off	Off

7. Ending Pump Operation

   To end the Pump Mode the operator is to select Neutral on the gearshift selector, then turn the pump request switch to Off and then select Road Mode. If Programmed, the inertia brake will engage in order to stop the tail shaft of the transmission from rotating to allow for easy shift into Road Mode.

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   Table 9

   Step	Gear Selected	Shift Selector Display	Vehicle Switches			Pump Mode Request Lamp	Positive Pump Engage Lamp	OK to Pump Lamp	Inertia Brake
   			Pump Mode Request switch J2:14	Positive Pump Engage J2:54	Gear Driver Output J2:11
   7	N	NN	Off	Off	Off	Off	Off	Off	Off

Wiring and Connections

Connectors

Illustration 8	g01741473
Series CX31 Transmission (Series CX35 Transmission similar in configuration) (1) 24 Pin Connector J3 (2) 70 Pin Connector J2

Illustration 9	g01741079
Series CX28 Transmission (3) 70-Pin Connector J2 (4) 24-Pin Connector J3

Two machine interface connectors are required for the vehicle. The 24-pin connector has the ignition switch and battery connections. The 70-pin ECU J2 terminal connector has the remaining switch inputs and J1939 data link connections. Please refer to Special Instruction, REHS2884, "Application and Installation Guide (Electrical) for the CX28, CX31, and CX35 On-Highway Transmissions".

Illustration 10	g01375193
70 Pin ECU J2 Terminal Connector

The connector for the chassis is the 70 pin ECU J2 terminal connector.

Note: Caterpillar does not recommend the use of nonconductive grease with this connector.

Torque of the Allen Head Bolt for the Terminal Connector

The torque for the Screw of the 70 Terminal ECU J2 Connector is 6 ± 1 N·m (53 ± 8.9 lb in). The screw requires a 4 mm (5/32 inch) hex wrench.

Size of the Wire Gauge

The maximum wire size is #14 AWG SAE J1128 type GXL. Recommended wire size is #16 or #18 AWG SAE J1128 type SXL, #16 or #18 AWG SAE J1128 type GXL or a wire of equivalent gauge and diameter.

Wire Insulation and Size Range

The diameter of the wire insulation must be within the following ranges in order to ensure proper sealing.

Table 10

Wire Type	Wire Gauge	Diameter of the Insulation
GXL	14	2.90 mm to 3.18 mm (0.114 inch to 0.125 inch)
	16	2.44 mm to 2.85 mm (0.096 inch to 0.112 inch)
	18	2.26 mm to 2.49 mm (0.089 inch to 0.098 inch)
SXL	16	2.95 mm to 3.33 mm (0.116 inch to 0.131 inch)
	18	2.62 mm to 3.00 mm (0.103 inch to 0.118 inch)

Part Numbers for Connectors, Sockets, and Plugs

Table 11

Required Parts for the Terminal Connector
Description	Usage	Vendor Part Number	Caterpillar Part Number
70 Terminal connector	ECU Harness of the Vehicle	Amp 776241-6	147-1446
AMP Gold Socket Contact Stamped formed	#16 & #18 AWG SXL and #14, #16 and #18 AWG GXL wire	Amp 638090-1	126-1766
Deutsch Gold Socket Contact machined for field service	#14 AWG SXL and #14 AWG GXL wire	Deutsch 0462-209-1631	126-1768
DeutschGold Socket Contact machined for field service	#16 & #18 AWG SXL and #16 and #18 AWG GXLwire	Deutsch 0462-201-1631	9X-3402
Sealing Plug #14 - 18 AWG	Sealing Unused Cavities of the Connector	PEI Genesis 225-0093-000	9G-3695
Sealing Plug #14 - 18 AWG	Sealing Unused Cavities of the Connector	Deutsch 11-4017	8T-8737

Guidelines for the Installation of the Connector Socket

It is critical that the harness supplier use the correct crimp tools and tool calibration set up procedures when installing AMP and Deutsch connector terminals. The following tables indicate the tooling for crimping, the criteria for go or no go, and the dimensions for crimping of each contact for the wire combination.

Note: AMP 776093-1 Stamped and Formed Socket with #16 and #18 AWG SXL wire or with #14, #16 or #18 AWG GXL wire is a Caterpillar part number 126-1766 Connector Socket .

Table 12

Wire Type	Wire Gauge	Height of the Crimp	Width of the Crimp
GXL	14	1.63 ± 0.05 mm (0.064 ± 0.002 inch)	2.5400 mm (0.10 inch)
	16	1.4986 ± 0.0508 mm (0.059 ± 0.002 inch)	2.5400 mm (0.10 inch)
	18	1.3716 ± 0.0508 mm (0.054 ± 0.002 inch)	2.5400 mm (0.10 inch)
SXL	16	1.3716 ± 0.0508 mm (0.054 ± 0.002 inch)	2.5400 mm (0.10 inch)
	14	1.4986 ± 0.0508 mm (0.059 ± 0.002 inch)	2.5400 mm (0.10 inch)

Note: The height of the crimp for the insulation barrel of the AMP 776093-1 stamped and formed sockets must be set according to the diameter of the insulation. The width of the crimp for all wire insulation is 3.68 mm (0.145 inch) maximum.

Table 13

Deutsch 0462-209-1631 Solid Socket with #14 AWG wire (Caterpillar Part Number 126-1768 Connector Socket )
Options for Crimp Tools	DIE	Locator	Go in inches	No Go in inches
Deutsch Hand Tool HDT-48-00	N/A	N/A	1.3208 mm (0.052 inch)	1.4478 mm (0.057 inch)
Pico Model 400	414DA-16N	4301-16	1.0922 mm (0.043 inch)	1.2700 mm (0.050 inch)

Table 14

Deutsch 0462-201-1631 Solid Socket with #16 and #18 AWG Wire (Caterpillar Part Number 9X-3402 Connector Socket )
Options for Crimp Tools	DIE	Locator	Go in inches	No Go in inches
Deutsch Hand Tool HDT-48-00	N/A	N/A	1.1430 mm (0.045 inch)	1.2700 mm (0.050 inch)
Pico Model 400	414DA-16N	4301-16	1.0922 mm (0.043 inch)	1.2700 mm (0.050 inch)

Sealing Plugs

Illustration 11	g01375202
Location of the Unused Connector Plug

Caterpillar requires sealing plugs for all unused connector cavities. Two options are available. Either the Deutsch 114017 (Caterpillar part number 8T-8737 Seal Plug ) or PEI Genesis 225-0093-000 (Caterpillar part number 9G-3695 Plug ) sealing plugs can be used. Correct installation of either of these cavity plugs is critical to maintaining integrity of the sealing surface for the remaining connectors. Illustration 11 indicates the correct insertion of the plug. The plug cap is designed to rest against the seal. The plug cap is not designed to be inserted into the hole in the seal.

Recommendations for Harness Routing

Illustration 12	g01375207

Ensure that the connector seals are not stressed when you route the harness. The harness cannot curve too close to the connector. Refer to Illustration 12. This applies to routing of OEM lines on or near the engine harness and the OEM ECU connector. When the harness curves too close to the connector, the connector seal is stretched away from the wire. The stretched seal provides a gap. Moisture can enter the gap. The wire routing should exit perpendicular to the connector before curving. The bend of harness bundle should have a radius of 2 times the diameter of the harness. In order to provide the correct bend radius for the wiring harness, Caterpillar recommends that the original equipment manufacturer form the harness. This will ensure the connector seal. Also, this can prevent abrasion of the harness.

Requirements for the Current of the Circuit

Switch Circuits

Switch circuits require less than 20 mA. The required minimum size of wire is 18 gauge. This ensures proper sealing at the ECM connector.

Lamp Circuits of the ECM

The Output Lamp of the Gear Indicator (J2: 11) will drive a maximum of 300 mA. The required minimum size of wire is 18 gauge. This ensures proper sealing at the ECM connector. The ECM provides a ground circuit to a lamp. The lamp is connected to the positive battery side.

Support of the Data Link for the Vehicle

The Series CX transmissions support both using either J1939 and J1587 data links. The SAE J1587 broadcast of the data link supports the displays of the instrument cluster.

The J1939 data link is supported for two-way communication.

Additional information is available in publication Special Instruction, REHS2884, "Application and Installation Guide (Electrical) for the CX28, CX31, and CX35 On-Highway Transmissions".

Note: The vehicle must not be equipped with any component that uses Source Address 0x05, or 0x06 except for Caterpillar approved shifter modules.