Case IH t3F – PSG (Fuel Pump Control Module) / EDC / EIC: PSG Message, Data Valid But Above Normal Range

This code indicates a communication or sensor value anomaly where the data transmitted from the injection pump's control module over the CAN bus is recognized as a valid message format, but the actual values exceed normal operating parameters. This is typically caused by internal failure of the PSG module, damaged wiring, or severe mechanical timing issues inside the pump caused by fuel aeration.

• MXM
• MXM120
• MXM130
• MXM140
• MXM155
• MXM175
• MXM190
• TM120
• TM130
• TM140
• TM155
• TM175
• TM190

1. 1

   Inspect the Wiring Harness: Check the 9-way electrical connector at the PSG (Fuel Pump Control Module) for corrosion, backed-out pins, or wire chafing. Damaged wires between the PSG and the fuel control solenoid can trigger erratic data.

2. 2

   Check for Fuel Aeration / Lift Pump Pressure: Verify your lift pump is supplying adequate pressure and that fuel filters are clean. Low supply pressure causes air to enter the fuel, which can damage the pump mechanically and cause the PSG to output out-of-range timing data.

3. 3

   Check for Accompanying Codes: Look for related codes like t40 (PSG Message, Shorted To High Source) which would definitively point to a dead short in the PSG wiring.

4. 4

   Clear and Retest: If the wiring is intact and supply fuel pressure is good, but the t3F code persists, the PSG module itself has likely failed internally.

1. 1

   Prep the Tractor

   Disconnect the negative battery cables at both batteries. Thoroughly wash the engine block around the injection pump to prevent dirt from entering the open fuel lines.

2. 2

   Disconnect Lines and Wiring

   Disconnect the 9-way electrical connector at the PSG. Remove the fuel return line (overflow valve) and the fuel supply line (banjo bolt) at the side of the pump. Have a rag ready to catch spilled diesel.

3. 3

   Remove High-Pressure Lines

   Remove the high-pressure fuel lines connecting the injection pump to the engine cylinders.

4. 4

   Clear Access

   Remove the intake air tube, accelerator pedal position sensor (APPS), and unbolt the engine oil dipstick tube to move it out of the way. Remove the crankcase vent hose and canister from the gear cover.

5. 5

   Remove Pump Gear

   Remove the access cover on the front timing gear housing. Remove the nut and washer retaining the injection pump gear to the VP44 pump shaft. Use a gear puller to carefully separate the gear from the tapered pump shaft (do not drop the keyway into the timing cover).

6. 6

   Remove the Pump

   Unbolt the injection pump mounting flange nuts and slide the VP44 pump out of the engine block.

7. 7

   Install the New Pump

   Ensure the engine is at Top Dead Center (TDC). Insert the remanufactured VP44 pump, ensuring the shaft keyway aligns perfectly with the timing gear. Torque the mounting nuts and the gear retaining nut to OEM specifications.

8. 8

   Reassembly and Bleeding

   Reinstall all high-pressure lines, supply lines, and the 9-way connector. Bump the starter to engage the electric lift pump for 30 seconds to bleed air from the low-pressure side of the system before attempting to start the tractor.