Case IH 15201 - AST – Advanced Steering (AST) / Steering Valve Controller (SVC): Steering valve controller battery voltage too low

The electrical voltage being supplied to the controller responsible for the tractor's advanced hydraulic steering system has dropped below the minimum operating threshold.

• MAXXUM T4E
• VESTRUM CVX
• Magnum Series (180, 200, 220, 240, 250, 280, 310, 340, 380)
• Vestrum CVX Series (100, 110, 120, 130)
• Farmall Series (115U, 40-50 CVT)
• Steiger & Quadtrac Series (AFS Connect)

1. 1

   Test the main battery voltage and the alternator charging output to ensure the primary electrical system is generating sufficient power (12V to 14V)

2. 2

   Inspect the wiring harness leading to the Steering Valve Controller (SVC) for chafing, pinched wires, or loose grounds

3. 3

   Disconnect the harness at the SVC and use a multimeter to measure the voltage at the power supply pins, comparing it to battery voltage to identify any voltage drop

4. 4

   Inspect the specific fuses and relays that supply power to the AST/SVC subsystem for corrosion or partial failure

1. 1

   Power Down

   Turn off the tractor, remove the key, and disconnect the negative battery cable to ensure safety.

2. 2

   Clean Power Sources

   Clean the main battery terminals, battery grounds, and chassis ground straps, as poor grounds are a primary cause of low voltage codes.

3. 3

   Inspect the Controller Connections

   Locate the Steering Valve Controller. Disconnect the main harness and inspect the pins for corrosion, moisture ingress, or pushed-out pins. Clean with electrical contact cleaner if necessary.

4. 4

   Repair Wiring

   If the diagnostic pin test revealed low voltage at the connector (but good voltage at the battery), trace the power circuit back to the fuse panel. Repair any damaged wires and replace any corroded fuses or relays on this circuit.

5. 5

   Replace the Controller (If Necessary)

   If the wiring provides full, stable battery voltage to the SVC but the 15201 code persists, the controller itself has an internal hardware fault and must be replaced.

6. 6

   Clear Codes

   Reconnect the battery. Access the on-board diagnostics to clear the fault stack by navigating the 'H menus' using the switches on the instrument cluster (Navigate to the R1 module, menu H3, and select the AST system), or by using a dealer diagnostic laptop.

7. 7

   Test Drive

   Operate the tractor and engage the steering system to ensure the code does not return.