Case IH 2726 – ZTC (Zone Tractor Controller): CAN message EEC2 signal PLACS error or not available.

The control module logging this code is expecting to receive the engine's current load percentage data over the CAN bus network, but the signal is either missing, corrupted, or out of the expected range. This usually points to a communication breakdown between the engine and the tractor's central network.

• Steiger T4B
• Case IH Steiger series
• Case IH STX series
• Case IH Magnum series
• Case IH Puma series

1. 1

   Check for Engine ECM Codes: Before chasing a wiring issue, check if the Engine ECM has logged any power, ground, or internal hardware faults (such as ENG 111 - Engine Controller Failure). If the Engine ECM is offline or in a severe derate, it will stop broadcasting the EEC2 message.

2. 2

   CAN Bus Resistance Test: Disconnect the battery and measure the resistance across the CAN High and CAN Low pins at the diagnostic port. A healthy CAN network should read exactly 60 ohms. If it reads 120 ohms, one of the terminating resistors is failed or disconnected. If it reads 0 ohms, the CAN lines are shorted together.

3. 3

   Harness Inspection: Visually inspect the wiring harness running between the Engine ECM and the ZTC. Look for chafing, pinched wires, or melted insulation, particularly near the engine block and transmission housing.

4. 4

   Connector Pin Check: Disconnect the harnesses at the ZTC and the Engine ECM. Inspect for pushed-out pins, water intrusion, or green corrosion, which can easily interrupt the low-voltage CAN signals.

1. 1

   Disconnect Power

   Turn off the key and disconnect the negative battery cable to protect the modules.

2. 2

   Repair CAN Wiring

   If the diagnostic checks revealed an open or shorted CAN wire, locate the damaged section. Splice and solder the CAN High or CAN Low wires, ensuring the twisted-pair shielding is maintained as closely as possible to prevent electromagnetic interference.

3. 3

   Replace Terminating Resistors

   If the CAN bus resistance was 120 ohms, locate the faulty 120-ohm terminating resistor on the network backbone and replace it.

4. 4

   Clean Connections

   If moisture or corrosion was found at the ZTC or ECM connectors, clean the pins with electronic contact cleaner and apply dielectric grease before reconnecting.

5. 5

   Software/Firmware Update

   If the wiring and resistors are perfectly intact, the issue may be a software handshake failure between the Engine ECM and the ZTC. A dealer will need to use the CNH Electronic Service Tool (EST) to flash the latest firmware to the ZTC and Engine ECM.

6. 6

   Clear Codes and Test

   Reconnect the battery, cycle the key, and clear the inactive fault codes. Start the tractor and monitor the "Percent Load" parameter on the display to verify the ZTC is receiving the EEC2 message.