The RPM control software is used for activation of the range solenoids.
It’s included in control unit for range shifting (DirectDrive transmission)
The RPM control software is used for shifting ranges in the DirectDrive transmission. The following signals are processed and implemented:
– Reverse drive lever position
– Shift unit position
– Engine speed
– Vehicle speed
– Operating mode settings

John Deere RPM fault codes / John Deere RPM diagnostic trouble codes

NOTE:This page only indicates the meaning of the fault codes. For complete troubleshooting information, see the technical manuals.

RPM 000168.04 (RPM 168.04)— Supply Voltage (BAT) Too Low
Supply voltage (BAT) below 9 V.

RPM 000628.02 (RPM 628.02)— Control Software Internal Fault
The diagnostic trouble code is generated if the control software detects a faulty EOL parameter during power-up. The parameters are replaced by default values.
Reaction of the control software: Limited or no function of the control software.

RPM 000630.02 (RPM 630.02)— Control Software Internal Fault
The diagnostic trouble code is generated if the control software detects that the internal memory contains an incorrect entry.
Reaction of the control software: Limited or no function of the control software.

RPM 521991.12 — Control Unit for Range Shifting, Temperature Too High
The diagnostic trouble code is generated if the control software detects that the temperature of the control unit for gear shifting is too high. This may occur if an extremely high number of shifts are performed in a short period of time.
Reaction of the control software: The ranges cannot be engaged.

RPM 521926.05 — Range C Solenoid Current Too Low
The diagnostic trouble code is generated if the control software detects that the current value at the solenoid is too low. This may indicate an open circuit.
Reaction of the control software: Limited or no function of the transmission.

RPM 521926.06 — Range C Solenoid Current Too High
The diagnostic trouble code is generated if the control software detects that the current value at the solenoid is too high. This may indicate a shorted circuit.
Reaction of the control software: Limited or no function of the transmission.

RPM 521926.07 — Range C Fault
The diagnostic trouble code is generated if the control software detects that after several attempts the range cannot be engaged. This indicates a mechanical problem. The range is disabled until the next tractor start-up.
Reaction of the control software: Limited or no function of the transmission.

RPM 521926.17 — Time-Out When Engaging Range C
This diagnostic trouble code is generated if the control software detects that it takes too long to engage the range. The second attempt to engage the range takes place automatically.

RPM 521926.18 — INFORMATION FOR OPERATOR: Range C Cannot Be Engaged
This diagnostic trouble code is generated if the control software detects that the second attempt to engage the range has failed. In its active state, this fault also generates the diagnostic trouble code for time-out when engaging the gear. The operator is prompted to engage the range again.
Reaction of the control software: Limited or no function of the transmission.

RPM 521927.05 — Range B Solenoid Current Too Low
The diagnostic trouble code is generated if the control software detects that the current value at the solenoid is too low. This may indicate an open circuit.
Reaction of the control software: Limited or no function of the transmission.

RPM 521927.06 — Range B Solenoid Current Too High
The diagnostic trouble code is generated if the control software detects that the current value at the solenoid is too high. This may indicate a shorted circuit.
Reaction of the control software: Limited or no function of the transmission.

RPM 521927.07 — Range B Fault
The diagnostic trouble code is generated if the control software detects that after several attempts the range cannot be engaged. This indicates a mechanical problem. The range is disabled until the next tractor start-up.
Reaction of the control software: Limited or no function of the transmission.

RPM 521927.17 — Time-Out When Engaging Range B
This diagnostic trouble code is generated if the control software detects that it takes too long to engage the range. The second attempt to engage the range takes place automatically.

RPM 521927.18 — INFORMATION FOR OPERATOR: Range B Cannot Be Engaged
This diagnostic trouble code is generated if the control software detects that the second attempt to engage the range has failed. In its active state, this fault also generates the diagnostic trouble code for time-out when engaging the gear. The operator is prompted to engage the range again.
Reaction of the control software: Limited or no function of the transmission.

RPM 521935.05 — Range A Solenoid Current Too Low
The diagnostic trouble code is generated if the control software detects that the current value at the solenoid is too low. This may indicate an open circuit.
Reaction of the control software: Limited or no function of the transmission.

RPM 521935.06 — Range A Solenoid Current Too High
The diagnostic trouble code is generated if the control software detects that the current value at the solenoid is too high. This may indicate a shorted circuit.
Reaction of the control software: Limited or no function of the transmission.

RPM 521935.07 — Range A Fault
The diagnostic trouble code is generated if the control software detects that after several attempts the range cannot be engaged. This indicates a mechanical problem. The range is disabled until the next tractor start-up.
Reaction of the control software: Limited or no function of the transmission.

RPM 521935.17 — Time-Out When Engaging Range A
This diagnostic trouble code is generated if the control software detects that it takes too long to engage the range. The second attempt to engage the range takes place automatically.

RPM 521935.18 — INFORMATION FOR OPERATOR: Range A Cannot Be Engaged
This diagnostic trouble code is generated if the control software detects that the second attempt to engage the range has failed. In its active state, this fault also generates the diagnostic trouble code for time-out when engaging the gear. The operator is prompted to engage the range again.
Reaction of the control software: Limited or no function of the transmission.

RPM 521991.06 — Control Unit for Range Shifting, Current Too High
Overall current strength of solenoid coils is too high. Control unit is in cooling phase. Gear shifting is not possible until 30 seconds have elapsed.
NOTE: This diagnostic trouble code can also be generated if the rear PTO is operated in an improper manner. For example, if the rear PTO speed is quickly switched back and forth between the speed ranges, without switching on the rear PTO. It is recommended to first set the rear PTO speed to neutral and then to the desired speed range.

RPM 521991.12 — Control Unit for Range Shifting, Temperature Too High
The diagnostic trouble code is generated if the control software detects that the temperature of the control unit for gear shifting is too high. This may occur if an extremely high number of shifts are performed in a short period of time.
Reaction of the control software: The ranges cannot be engaged.