Procedure to Troubleshoot the Transmission Speed Sensor on Certain Material Handlers, Mobile Hydraulic Power Units, and Wheeled Excavators {3030} Caterpillar

Material Handler

MH3022 (S/N: FM21-UP; FB31-UP)

MH3024 (S/N: FM41-UP; FB51-UP)

Mobile Hydraulic Power Unit

M315D MHPU (S/N: H9A1-UP)

M318F OEM (S/N: MH91-UP)

Wheeled Excavator

M313D (S/N: K3D1-UP)

M314F (S/N: FB41-UP; F4A1-UP)

M315D (S/N: K5E1-UP)

M315D OEM (S/N: EY21-UP)

M315D2 (S/N: CH31-UP; CA41-UP)

M315F (S/N: F4D1-UP)

M316F (S/N: FB61-UP; F6N1-UP)

M317D2 (S/N: CH51-UP; CA61-UP)

M317F (S/N: F6P1-UP)

M318D (S/N: P8L1-UP; P9M1-UP; D9X1-UP)

M318F (S/N: FB81-UP; F8B1-UP)

M320D2 (S/N: EN81-UP; CH91-UP)

M320F (S/N: FB21-UP; F2W1-UP)

M322D (S/N: P3W1-UP; D3X1-UP)

M322D2 (S/N: EN21-UP)

M322F (S/N: FBW1-UP; F2Z1-UP)

Introduction

This Special Instruction contains the procedure to troubleshoot the transmission speed sensor on the machines listed above.

Do not perform any procedure in this Special Instruction until you have read the information and you understand the information.

Required Parts

Troubleshooting Procedure

If one or more of the following errors occurred, follow the"Troubleshooting Procedure for D/F Series".

• Logged error code - 191-02 or 191-11

• "Limp Home Mode" is active, and displayed as such on the monitor.

• Transmission operates only in First gear, and will not shift up to second gear.

• Engine speed is limited to 1300 rpm or less.

• Monitor displays "Power Train Error".

Troubleshooting Procedure for D/F Series

Note: A 7X-1710 Multimeter Probe can be used in place of the test harness.

Illustration 1	g06210970
Test Harness Pin A - Ground, Pin B - Signal and Pin C - +24V (D) Signal (E) Ground (F) 102-8803 Receptacle Kit (G) 155-2260 Connecting Plug Kit

1. Using ET, check all active and logged fault codes.

2. If the only logged fault code is 191-02, the code is likely the result of dissenting information in the signal chain from the transmission speed sensor to the machine ECM.

3. Using ET, clear all logged fault codes.

4. Drive the machine for 2 minutes, in both forward and reverse directions, reaching highest speed possible, in both first and second gear.

5. Check again for active and logged fault codes in ET.

6. If no error codes are active or logged, the speed sensor is not defective. Perform Steps 2 and 4 of the"Swivel Testing Procedure (Transmission Speed Sensor Circuits Only)". If no error codes are active or logged, no further testing is required.

7. If new fault codes 191-02 or 191-11 are logged, then follow the instructions in Step 8 through Step 17.

8. Inspect all three connection points (J), (K), and (L) from the speed sensor wiring. Refer to Illustration 2.
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   Illustration 2	g06210961
   Typical example Connection points - undercarriage harness (J) Connection to transmission speed sensor (K) Connection to swivel

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   Illustration 3	g06210973
   Typical example Detail view of H D-series (L) Swivel

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   Illustration 4	g06210974
   Typical example Detail view of H F-series (L) Swivel

9. Ensure that there is no corrosion on the connector pins or sockets. Ensure that there is no moisture or humidity in the connectors. Refer to Illustration 2.

10. Disconnect the undercarriage harness (J) from the speed sensor and check if a 24 V supply is present between "Pin C (+24V)" and "Pin A (Ground)". Refer to Illustration 2.

11. Connect the undercarriage harness back to the sensor.

12. Fabricate the test harness. Refer to Illustration 1. Connect the test harness (F) and (G) between the undercarriage harness and the harness from the swivel at point (K). Refer to Illustration 1 and Illustration 2.

13. Connect the 237-5130 Digital Multimeter Gp to the test harness at connection points (C) and (D) (signal and ground). Refer to Illustration 1.

14. Remove the transmission speed sensor from the transmission. Wipe away any transmission oil from the face of the sensor.

15. Hold the speed sensor in your hand and away from any metal. Record the output voltage.

16. Hold a piece of ferrous metal against the sensor face. Record the output voltage.

17. Repeat Step 15 and Step 16 three times to determine the average output of the sensor.

Compare your measurements with the values in the table below.

If your measurements are within the ranges for "high" and "low", the speed sensor is working correctly. Do not replace the sensor.

If the output voltage is not within the ranges listed in the above table, the speed sensor is not working correctly. The speed sensor can be considered as defective, especially if the output voltage for 'high' is significantly below 4.4V. Replace the sensor and test to ensure that the fault condition is cleared. Please provide your measurements in the claim story.

If the tests above do not identify the causes of sensor failure, perform the"Swivel Testing Procedure (Transmission Speed Sensor Circuits Only)".

Swivel Testing Procedure (Transmission Speed Sensor Circuits Only)

1. Delete all logged error codes.

2. With the service brake set, operate the machine by rotating the upper frame and moving the boom and stick.

3. Release the service brake, and travel in first and second gear, and if possible under differing underfoot conditions.

4. Check for logged error codes.

5. If fault code 191-11 is logged, disconnect the speed sensor from the undercarriage machine harness. Then disconnect the upper carriage machine harness at the electric swivel.
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   Illustration 5	g06211049
   Bypass harness for D-series models (F) 102-8803 Receptacle Kit (G) 155-2260 Connecting Plug Kit (M) 7500 mm (295.2 inch)

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   Illustration 6	g06211052
   Connection locations for bypass harness (D-Series machines) (F) 102-8803 Receptacle Kit (G) 155-2260 Connecting Plug Kit

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   Illustration 7	g06211053
   Bypass harness for F-series models (G) 155-2260 Connecting Plug Kit (N) 230-4009 Connector Plug As (P) 230-4010 Connector Receptacle As (R) 300 mm (11.8 inch) (S) 7500 mm (295.2 inch)

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   Illustration 8	g06211055
   Connection locations for bypass harness (F-series machines) (G) 155-2260 Connecting Plug Kit (N) 230-4009 Connector Plug As (P) 230-4010 Connector Receptacle As

6. Create a bypass harness by connecting the bypass harness at the undercarriage speed sensor harness (G) and the upper carriage machine harness at the electric swivel. For D-series (F) and for F-series (N) / (P).

   Bypass harness for D-series models, refer to Illustration 5.

   Bypass harness for F-series models, refer to Illustration 7. (Connection (N) has to be connected to swivel and connection (P) has to be connected to upper carriage machine harness).

   This bypass harness is created in order to bypass the electrical swivel and undercarriage electrical harness. (Transmission speed sensor circuits only).

   The bypass harness should be approximately 7500 mm (295.2 inch) long.

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   NOTICE
   Do not rotate the upper frame when using the bypass harness. Rotating the upper frame may twist and pull the bypass harness damaging the speed sensor and/or machine harness.

7. Delete all logged error codes, and travel in first and second gear.

8. Check for logged error codes. If no error codes are active after bypassing the electrical swivel, the electric swivel is most likely causing the fault.

9. Replace the electric swivel and retest to ensure that the fault condition is cleared.

10. Inspect all connections between the sensor and the machine ECM to verify that the connections are good.

If the issue is unresolved with the tests above, create a GDSN Product Health Service Request (SR) with a description of what steps have been done, reference this publication and attach a PSR prior to submitting to Caterpillar.