Massey Ferguson E 168 (16) – Engine Control Unit (ECU) / Electronic Engine Management (EEM3 or EEM4): Battery voltage ABOVE NORMAL

The system has detected an electrical potential (voltage) that is too high for safe operation. Specifically, the threshold for this code is typically triggered when the voltage exceeds 17V on a 12V system or 32V on a 24V system.

• 5400 Series
• 6400 Series
• 7600 Series
• 7700 Series
• 8600 Series
• 9695
• 9795
• 5S Series
• 6S Series
• 7S Series
• 8S Series

1. 1

   Verify that there is no unrecommended use of a booster pack, jump-starter, or external battery charger connected to the machine, as these can cause temporary voltage spikes.

2. 2

   Measure the battery voltage across the terminals with the engine off. It should read around 12.6V.

3. 3

   Start the engine and measure the voltage at the battery terminals. If the reading climbs above 15V (and especially if it approaches 17V), the alternator's internal voltage regulator has failed and is overcharging the system.

4. 4

   Check the alternator and battery wiring harnesses for any shorts to a high-voltage source.

1. 1

   Disconnect Power

   Turn off the engine and disconnect the negative (-) battery cable to prevent electrical shorts and ensure safety.

2. 2

   Remove the Drive Belt

   Relieve the tension on the engine drive belt/serpentine belt and slip it off the alternator pulley.

3. 3

   Disconnect the Alternator

   Unbolt the electrical connections (B+ terminal and connector plugs) from the rear of the alternator.

4. 4

   Remove the Alternator

   Remove the mounting bolts securing the alternator to the engine bracket and carefully extract the faulty unit.

5. 5

   Install the New Alternator

   Position the replacement alternator, insert and tighten the mounting bolts to OEM specifications, and reconnect the electrical terminals securely.

6. 6

   Reinstall the Belt

   Route the drive belt back over the alternator pulley and restore proper belt tension.

7. 7

   Inspect the Battery

   Because an overcharging alternator boils battery acid, carefully inspect the battery for swelling, leaks, or a strong sulfur smell. Replace the battery if it has been damaged by the high voltage.

8. 8

   Test and Clear Codes

   Reconnect the negative battery cable. Start the tractor and verify with a multimeter that the charging voltage is now stable (typically between 13.5V and 14.5V). Use a diagnostic tool to clear the E 168 (16) fault code from the ECU.