Case IH 74 – ECM (Engine Control Module) / Transmission ECU / TCU (Tractor Control Unit): ECM SUPPLY VOLTAGE (12VF) IS TOO LOW (Code 74) / PTO is commanded off but the PTO speed is greater than zero (Code 5014)

Code 74: The Engine Control Module (ECM) or Transmission ECU detects that the supply voltage at ECM connector 2 (pin 34 or pin 10) has dropped below 9 volts for longer than 0.3 seconds, critically disabling the transmission. Code 5014: The Tractor Control Unit (TCU) detects PTO shaft rotation after the PTO switch has been in the Off position for 45 seconds.

• MX Maxxum
• Case IH MX series
• Maxxum
• Puma
• CX series

1. 1

   (Code 74 - Voltage Issue) Test the battery voltage and state of charge

2. 2

   (Code 74 - Voltage Issue) Test the alternator output to ensure it is properly charging the system

3. 3

   (Code 74 - Voltage Issue) Check the ECU supply fuses (e.g., Fuse F1 - 10A)

4. 4

   (Code 74 - Voltage Issue) Disconnect the ECM connections and check the wiring harness for continuity, shorts, or open circuits between the battery/alternator and the ECM pins (connector 2, pin 34 or pin 10)

5. 5

   (Code 5014 - PTO Issue) Check if the PTO-driven implement has high inertia and is physically causing the rotation

6. 6

   (Code 5014 - PTO Issue) Test if hydraulic pressure is present at the PTO pressure test port when the PTO switch is in the Off position. A reading greater than 0 indicates a sticking valve spool

7. 7

   (Code 5014 - PTO Issue) Inspect the PTO brake friction plates and disc springs for excessive wear

1. 1

   Recharge or replace

   (Code 74) Recharge or replace the battery if it fails a load test.

2. 2

   Replace

   (Code 74) Replace the alternator if it is not outputting sufficient voltage.

3. 3

   Replace and repair

   (Code 74) Replace any blown fuses and repair damaged wiring in the ECM supply circuit.

4. 4

   Clear and verify

   (Code 74) Clear the fault codes and cycle the key to verify the voltage has returned to normal parameters.

5. 5

   Clear and return

   (Code 5014) If the implement is causing the rotation, no tractor repair is needed; clear the fault codes and return the unit to field operation.

6. 6

   Clean or replace

   (Code 5014) If hydraulic pressure is present when the PTO is off, remove and clean the PTO control valve. Replace the sticking valve spool if it is scored or damaged.

7. 7

   Replace

   (Code 5014) If the valve is functioning properly but the shaft still spins, split the PTO housing and replace the worn PTO brake friction plates and disc springs.

8. 8

   Replace

   (Code 5014) If the PTO switch itself is physically failing to send the 'Off' signal, replace the switch.