Doosan 12/150, Operation And Maintenance Mannual

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ENGINE TROUBLESHOOTING

12/150_23136625

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C  en

INTERMITTENT FAULT DIAGNOSTICS 

(WITH ELECTRONIC CONTROLS)

Intermittent faults are problems that periodically “go away”. A

problem such as a terminal that intermittently doesn’t make contact

can cause an intermittent fault. Other intermittent may be set only

under certain operating conditions such as heavy load, extended

idle, etc. When diagnosing intermittent faults, take special note of the

condition of wiring and connectors, since a high percentage of

intermittent problems originate here. Check for loose, dirty or

disconnected connectors. Inspect the wiring routing, looking for

possible shorts caused by contact with external parts (for example,

rubbing against sharp sheet metal edges). Inspect the connector

vicinity, looking for wires that have pulled out of connectors, poorly

positioned terminals, damaged connectors and corroded or

damaged splices and terminals. Look for broken wires, damaged

splices, and wire

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to

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wire shorts. Use good judgement if component

replacement is thought to be required.

NOTE: The engine control unit (ECU) is the component LEAST

likely to fail.

Suggestions for diagnosing intermittent faults:

If the problem is intermittent, try to reproduce the operating

conditions that were present when the diagnostic trouble code

(DTC) set.

Observing these values   can help determine the operating

conditions when the fault occurred.  

If a faulty connection or wire is suspected to be the cause of the

intermittent problem: clear DTCs, then check the connection or

wire by wiggling it while watching the diagnostic gauge to see if

the fault resets.

Possible causes of intermittent faults:

Faulty connection between sensor and actuator harness.

Faulty contact between terminals in connector.

Faulty terminal/wire connection.

Electromagnetic interference (EMI) from an improperly installed

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way radio, etc., can cause faulty signals to be sent to the ECU.

STORAGE

Engine Storage Guidelines

1. Engines can be stored outside for up to three (3) months with no

long term preparation IF COVERED BY WATERPROOF

COVERING.

2. Engines can be stored in a standard overseas shipping container

for up to three (3) months with no long term preparation.

3. Engines can be stored inside, warehoused, for up to six (6)

months with no long term preparation.

Engines expected to be stored more than six (6) months, long term

storage preparation MUST BE taken.  

Preparing Engine for Long Term Storage

The following storage preparations are good for long term engine

storage up to one year. After that, the engine should be started,

warmed up, and retreated for an extended storage period.

IMPORTANT: Any time your engine will not be used for over six

(6) months, the following recommendations for storing it and

removing it from storage will help to minimize corrosion and

deterioration.

1. Change engine oil and replace filter. Used oil will not give

adequate protection. 

2. Service air cleaner.  

3. Draining and flushing of cooling system is not necessary if

engine is to be stored only for several months. However, for

extended storage periods of a year or longer, it is recommended

that the cooling system be drained, flushed, and refilled. Refill

with appropriate coolant.  

4. Crank the engine several revolutions with starter (do not allow

the engine to start).

5. Remove fan/alternator poly

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vee belt, if desired.

6. Remove and clean batteries. Store them in a cool, dry place and

keep them fully charged.

7. Disengage the clutch for any driveline.

8. Clean the exterior of the engine with salt

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free water and touchup

any scratched or chipped painted surfaces with a good quality

paint.

9. Coat all exposed (machined) metal surfaces with grease or

corrosion inhibitor if not feasible to paint.

10. Seal all openings on engine with plastic bags and tape.

11. Store the engine in a dry protected place. If engine must be

stored outside, cover it with a waterproof canvas or other suitable

protective material and use a strong waterproof tape.

Removing Engine from Long Term Storage

Refer to the appropriate section for detailed services listed below or

have your authorized servicing dealer or engine distributor perform

services that you may not be familiar with.

1. Remove all protective coverings from engine. Unseal all

openings in engine and remove covering from electrical systems.

2. Remove the batteries from storage. Install batteries (fully

charged) and connect the terminals.

3. Install fan/alternator poly

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vee belt if removed.

4. Fill fuel tank.

5. Perform all appropriate pre

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starting checks.  

IMPORTANT: DO NOT operate starter more than 30 seconds at

a time. Wait at least 2 minutes for starter to cool before trying

again.

6. Crank engine for 20 seconds with starter (do not allow the engine

to start). Wait 2 minutes and crank engine an additional 20

seconds to assure bearing surfaces are adequately lubricated.

7. Start engine and run at low idle and no load for several minutes.

Warm up carefully and check all gauges before placing engine

under load.

8. On the first day of operation after storage, check overall engine

for leaks and check all gauges for correct operation.