Case IH F-168-18 - ECU – Engine Control Unit (ECU): Battery voltage is lower than expected

The control unit has detected that the unswitched battery supply circuit voltage has dropped below the acceptable operational range.

• MAGNUM AFS Connect
• Austoft 9900 Sugarcane Harvesters
• Puma Series
• CVX Series (140, 150, 160, 175, 195)
• Magnum Series
• Steiger Series
• Quadtrac Series
• MX Series
• 7000/9000 series tractors

1. 1

   Measure the battery voltage with a multimeter (should read 12.4V - 12.7V when engine is off, and 13.5V - 14.5V when running)

2. 2

   Visually inspect the battery for physical damage, leaking, or age

3. 3

   Inspect the wiring harness and contacts from the battery to the Engine ECU for loose connections, bad grounds, or corrosion

4. 4

   Check the working condition of the alternator/generator to ensure it is actively charging the system when the engine is running

1. 1

   Disconnect battery

   Disconnect the negative battery cable before performing any electrical repairs.

2. 2

   Clean connections

   Clean all battery terminals, cable ends, and chassis ground connections using a wire brush and battery cleaner. Reconnect and tighten them securely.

3. 3

   Replace battery

   If the battery failed the voltage or load test, remove the battery hold-down bracket, extract the old battery, and install a new heavy-duty 12V battery.

4. 4

   Remove drive belt

   If the alternator failed the charging test (outputting less than 13.5V while running), relieve the tension on the serpentine/drive belt and remove the belt from the alternator pulley.

5. 5

   Disconnect alternator wiring

   Disconnect the electrical connections (B+, ground, and sensor wires) from the back of the alternator.

6. 6

   Remove alternator

   Remove the alternator mounting bolts and extract the faulty alternator.

7. 7

   Install new alternator

   Install the new alternator, torque the mounting bolts to OEM spec, reconnect the electrical terminals, and reinstall the drive belt.

8. 8

   Verify charging voltage

   Reconnect the battery, start the engine, and verify that the charging voltage at the battery is now within the 13.5V - 14.5V range.

9. 9

   Clear fault code

   Use a diagnostic scan tool to clear the F-168-18 fault code from the ECU.