Kohler 80REOZJF, 100REOZJF, 150REOZJF, 200REOZJF, 125REOZJG, 180REOZJG, 230REOZJE, 250REOZJE, 275REOZJE, 300REOZJ, 350REOZJ, 400REOZJ, 500REOZJ, 350REOZJB, 400REOZJB, 500REOZJB Maintenance Manual (tp7138)

These Kohler REOZJ-series generator sets usually sit in plant rooms, rooftops, or outdoor enclosures, kicking in when the main power drops or carrying steady load in industrial yards. This maintenance manual is what I keep nearby to plan routine service and to double-check I’m not missing any inspections that will shorten the life of the engine or alternator. When a unit starts taking longer to pick up load or shows unstable voltage after a service, I use this book to retrace what was touched, verify adjustments, and confirm the maintenance intervals were followed.

Applications & Use Cases

• Plan routine services so fuel, lube, cooling, and air systems are inspected on time and not just when something fails.
• Set up service checklists for multiple units so every generator in the fleet is treated the same way.
• Trace performance issues after a recent service by confirming what should have been inspected or replaced.
• Verify adjustments and clearances after component replacement to avoid premature wear.
• Document work done in line with the manual’s schedules, useful for warranty support and resale.

FAQ

Q: Can I keep this manual on a tablet in the generator room?

A: Yes, it’s practical to use digitally; you can zoom diagrams and search text while you work beside the unit.

Q: Is it worth printing parts of this manual?

A: Many techs print the key service intervals and inspection checklists to keep in a binder on the wall near the genset.

Safety Note

Always lock out the generator and verify it cannot start automatically before opening panels or touching wiring.

Kohler 80REOZJF, 100REOZJF, 150REOZJF, 200REOZJF, 125REOZJG, 180REOZJG, 230REOZJE, 250REOZJE, 275REOZJE, 300REOZJ, 350REOZJ, 400REOZJ, 500REOZJ, 350REOZJB, 400REOZJB, 500REOZJB Maintenance Manual (tp7138) Index:

Safety Precautions …………………………………………. 2
Introduction …………………………………………………. 2
General information ………………………………………. 5
About this Workshop Manual …………………………. 5
Spare parts …………………………………………………. 5
Certified engines ………………………………………….. 5
Service procedures ……………………………………….. 6
Our joint responsibility …………………………………… 6
Tightening torques ……………………………………….. 6
Torque-angle tightening …………………………………. 7
Lock nuts ……………………………………………………. 7
Strength classes ………………………………………….. 7
Sealant ………………………………………………………. 7
General ………………………………………………………… 8
Location of engine signs ……………………………….. 8
Tools ……………………………………………………………. 9
Special tools ……………………………………………….. 9
Technical data …………………………………………….. 10
Design and function …………………………………….. 12
The EMS 2 system …………………………………….. 12
Component description, sensors and monitors … 15
Control module (EMS 2) ………………………………. 18
Control Interface Unit (CIU) ………………………….. 18
Unit injector ……………………………………………….. 19
Alternator ………………………………………………….. 19
Starter ………………………………………………………. 19
Component location ……………………………………. 20
Limit values ………………………………………………… 21
Limit values, control module (EMS 2)
TAD1640–1642GE, TWD1643GE………………….. 21
Limit values, control module (EMS 2)
TAD1641–1643VE, TAD1650VE …………………… 23
Limp-Home function ……………………………………. 26
Service procedures ……………………………………… 27
When working with EMS 2 …………………………… 27
Control module (EMS 2), replace ………………….. 28
Unit injector, replacing ………………………………….. 29
Starting with auxiliary batteries …………………….. 30
Function check ……………………………………………. 31
Diagnostic function for VODIA ……………………… 31
Fault tracing ……………………………………………….. 32
Symptoms and possible causes …………………… 32
Diagnostic function ………………………………………. 33
Malfunction message ………………………………….. 33
Effect on engine ………………………………………….. 33
Operation …………………………………………………… 34
Fault codes (EMS 2) …………………………………….. 36
Electrical fault tracing ………………………………….. 46
General …………………………………………………….. 46
Functional check of wiring and
connector blocks ………………………………………… 46
Functional check of wiring and connector blocks 47
Splicing cables for cable connectors ……………… 48
Checking/fault tracing components ……………….. 49
Electrical system …………………………………………. 57
Important information – electrical system ……….. 57
Electrical system, overview …………………………. 68
Wiring diagram EMS 2 ………………………………… 60
Wiring diagram CIU …………………………………….. 61
Wiring diagram DCU ……………………………………. 62

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