The Detector 12 (optional) is a generator-set controller. It is used on generator sets from Cummins/Onan, including the 100 DGDB, 12.5 RDJC, 15.0 RDJC and 35 DGBB.
| Code | Meaning | Cause |
|---|---|---|
| FAULT 1 | The FAULT 1 or FAULT 2 fault lamp lights. Engine shuts down immediately, engine runs for several seconds and then shuts down, or engine continues to run | The standard undesignated fault functions are programmed to shut down the set when a fault is sensed. Fault 1 is time delayed while Fault 2 is immediate. The nature of the fault is an optional selection that is determined when the set installation is designed. The undesignated fault functions may also be programmed for non-shutdown or non-time delay |
| FAULT 2 | The FAULT 1 or FAULT 2 fault lamp lights. Engine shuts down immediately, engine runs for several seconds and then shuts down, or engine continues to run | The standard undesignated fault functions are programmed to shut down the set when a fault is sensed. Fault 1 is time delayed while Fault 2 is immediate. The nature of the fault is an optional selection that is determined when the set installation is designed. The undesignated fault functions may also be programmed for non-shutdown or non-time delay |
| HI ENG TEMP | Engine has shut down because of critically high temperature. | |
| LO ENG TEMP | Engine temperature is marginally low for starting. Indicates inoperative coolant heater, (Lamp lights when engine water jacket temperature is 70°F (21 OC) or lower. Since the lamp goes out after the engine warms up there should be no cause for alarm even during initial generator set operation.) | |
| LO FUEL | Fuel supply is marginally low. | |
| LO OIL PRES | Engine has shut down because of critically low oil pressure. | |
| OVERCRANK | Starter has been locked out because of excessive cranking time. | |
| OVERSPEED | Engine has shut down because of excessive speed. |
| Symptom | Cause | Remedy |
|---|---|---|
| Cranking does not stop automatically when engine comes up to speed | Centrifugal switch and start-disconnect relay | Hold start switch to ON until the centrifugal switch automatically disengages starter motor |
| Emergency stop resulting from low oil pressure or high water temperature condition | Dangerously high coolant (water) temperature or low oil pressure | Investigate and correct the cause; press reset button on control panel before restarting |
| Engine does not start (blue-white exhaust smoke; engine is getting fuel) | Air heater element does not glow red within 30 seconds | Observe air heater through air inlet hole or by removing air cleaner; engage preheat; check air heater and glow plug wiring: connections tight? free from corrosion? |
| Engine does not start (little or no exhaust smoke; engine is not getting fuel) | Fuel system not primed | Prime fuel system; observe fuel flow from return line |
| Engine does not start in cold temperatures below 32°F (0°C) | Incorrect fuel or oil viscosity; batteries not fully charged | Use Number 1 diesel fuel; use correct viscosity oil; keep batteries fully charged; do not use ether starting aid |
| Engine fails to start in 45 to 120 seconds (cranking limiter trips and cranking stops) | Wait one minute before resetting the cranking limiter and trying to start the engine | |
| Engine fails to start or starts, runs and then stops | Refer to Troubleshooting charts in the Operator’s Manual | |
| Engine runs and then shuts down, OVERSPEED lamp lights | Indicates engine has exceeded normal operating speed | Contact an authorized service center for service |
| Engine starts from generator control panel but will not start automatically or from a remote panel. (Note: The Run/Stop/Remote switch must be in the Remote position for automatic or remote starting) | Remote circuit breaker is tripped | Reset breaker and restart; contact an authorized service center if breaker trips after resetting |
| Engine will not crank | Indicates possible fault with control or starting system | Check for the following conditions: fault lamp on, correct fault and reset control; poor battery cable connections, clean the battery cable terminals and tighten all connections; discharged or defective battery, recharge or replace the battery; emergency stop button (if equipped) pushed in, to reset, pull switch out and move Run/Stop/Remote switch to Stop position, then push test switch to Reset/Lamp position; contact an authorized service center if none of the above |
| Fault lamp lights but no fault exists. Engine gauges show oil pressure, engine temperature, and frequency (speed) are within normal limits | The monitor board or a sensor may be at fault | Contact an authorized service center for service |
| Green RUN lamp does not light following engine start-up | Possible Start/Disconnect relay failure | Contact an Onan Dealer or Distributor for assistance. |
| Green RUN lamp does not light following engine startup | Indicates possible Start/Disconnect relay failure | Contact an authorized service center for assistance |
| Green RUN lamp lights following engine start-up | Indicates all engine systems are normal. No corrective action required. | |
| Green RUN lamp lights following engine startup | Indicates all engine systems are normal | No corrective action required |
| HI ENG TEMP lamp lights. Engine shuts down | Indicates engine has overheated (engine temperature has risen above 222°F/106°C) or coolant level is low (sets with coolant level sensor) | Allow engine to cool down completely before proceeding with the following checks: check coolant level and replenish if low, look for possible coolant leakage points and repair if necessary; check for obstructions to cooling airflow and correct as necessary; check for a slipping fan belt and tighten if loose; reset control and restart after locating and correcting problem; contact an authorized service center for service if none of the above |
| LO ENG TEMP lamp lights. Set is in standby mode but is not operating. (Lamp lights when engine coolant temperature is 70 °F (21 °C) or lower. Since the lamp goes out after the engine warms up, there should be no cause for alarm even during initial generator set operation.) | Engine coolant heater is not operating, is not circulating coolant, or ambient temperature has exceeded capability of heater | Check for the following conditions: coolant heater not connected to power supply — check for blown fuse or disconnected heater cord and correct as required; check for low coolant level and replenish if required, look for possible coolant leakage points and repair as required; contact an authorized service center if none of the above |
| LO ENG TEMP lamp lights. Set is in standby mode but is not operating. (Lamp lights when engine coolant temperature is 70°F (21°C) or lower. Since the lamp goes out after the engine warms up, there should be no cause for alarm even during initial generator set operation.) | Indicates engine coolant heater is not operating or is not circulating coolant | Check for the following conditions: coolant heater not connected to power supply, check for blown fuse or disconnected heater cord and correct as required; check for low coolant level and replenish if required, look for possible coolant leakage points and repair as required; contact an authorized service center for service if none of the above |
| LO FUEL LAMP lights. Engine shuts down and LO OIL PRES lamp lights | Indicates engine has run out of fuel | Check fuel level and replenish as required |
| LO FUEL lamp lights. Engine continues to run | Indicates diesel fuel supply is running low | Check fuel supply and replenish as required |
| LO FUEL lamp lights. Engine shuts down and LO OIL PRES lamp lights | Engine has run out of fuel | Check fuel level and replenish as required. |
| LO OIL PRES lamp lights. Engine shuts down | Indicates engine oil pressure has dropped to 14 psi (97 kPa) | Check oil level, lines and filters; if oil system is OK but oil level is low, replenish; reset control and restart; contact an authorized service center if oil pressure is not in the range of 25 to 40 psi (172 to 275 kPa) |
| No AC output voltage | Field breaker is tripped | Reset breaker; contact an authorized service center if voltage buildup causes breaker to trip |
| OVERCRANK lamp lights and engine stops cranking, or Engine runs, shuts down, and LO OIL PRES lamp lights | Possible fuel system problem | Check for empty fuel tank, fuel leaks, or plugged fuel lines and correct as required; Check for dirty fuel filter and replace if necessary (see MAINTENANCE section); Check for dirty or plugged air filter and replace if necessary (see MAINTENANCE section); Refer to Step 5; Reset the control and restart after correcting the problem. Contact an Onan Dealer or Distributor for service if none of the above. |
| OVERCRANK lamp lights and engine stops cranking, or engine runs, shuts down, and LO OIL PRES lamp lights | Indicates possible fuel system problem | Check for empty fuel tank, fuel leaks, or plugged fuel lines and correct as required; check for dirty fuel filter and replace if necessary (see Maintenance section); check for dirty or plugged air filter and replace if necessary (see Maintenance section); reset the control and restart after correcting the problem; contact an authorized service center for service if none of the above |
| PRE HI ENGINE TEMP lamp lights. Engine continues to operate | Indicates engine has begun to overheat and engine temperature has risen to approximately 215°F (102°C) | If generator is powering non-critical and critical loads and cannot be shut down, reduce load if possible by turning off non-critical loads; check air inlets and outlets and remove any obstructions to airflow; if engine can be stopped, follow procedure in step 3 |
| PRE LO OIL PRES lamp lights. Engine continues to operate | Indicates engine oil pressure has dropped to 20 psi (138 kPa) | If generator is powering critical loads and cannot be shut down, wait until next shutdown period and then follow step 5 procedure; if engine can be stopped, follow procedures in step 5 |
| SWITCH OFF lamp flashes | Indicates Run/Stop/Remote switch is in the Stop position which will prevent automatic starting if an automatic transfer switch is used | Move the Run/Stop/Remote switch to the Remote position for automatic starting |
| Stop circuit fails | Push governor arm down to shut off fuel in injection pump |
Fault codes and symptom→remedy steps extracted from this controller’s service/owner documentation; verify against the official manual before servicing. Aggregated from the service documentation of generator sets built on this controller.