P0685 - main relay (unexpected intervention)
- Make
- Fiat
- Model
- Croma Factory Service Manual
- Year
- 2005–2010
- Section
- Examiner - electronic diesel management › P0685 - main relay (unexpected intervention)
P0685 - MAIN RELAY (UNEXPECTED INTERVENTION)
The diagnostic equipment signals: Error P0685 (main relay), with detail "unexpected intervention"
This error is detected if the main relay switches off too quickly. If the main relay switches off too quickly during a period of inactivity for the control unit, the fault codes will not be memorized.
| 0 | Preliminary checks | ALL OK | PROBLEMS ENCOUNTERED | ACTION |
|---|---|---|---|---|
| Select the following system on the diagnostic equipment: EDC16C39 Diesel electronic injection system. Delete the errors present and turn the ignition key OFF. Wait until the engine management control unit switches off (min. 20 seconds.). Note: The main relay is switched off. If the engine is very hot, the fans remain on after the ignition is switched off. In this case, the control unit switches off automatically 10 secs after the fans are switched off. | Move on to Step 1 | |||
| 1 | Check on operation of main relay | ALL OK | PROBLEMS ENCOUNTERED | ACTION |
Errors check. Drive the vehicle in different driving conditions (engine speed and engine load) for a long stretch. Listen out for unusual noises and other system irregularities. At the end of the road test, check that none of the following errors is present using the diagnostic equipment:
| End of diagnosis | 1.The engine is not running smoothly | 1.Proceed as instructed in the fault diagnosis See table D003 ENGINE NOT RUNNING SMOOTHLY / (IRREGULAR OPERATION) | |
| 2.The engine is losing power | 1.Proceed as instructed in the fault diagnosis | |||
| 3.The engine does not produce maximum performance | 1.Proceed as instructed in the fault diagnosis | |||
| 4.The engine response is poor | 1.Proceed as instructed in the fault diagnosis See table D016 ADDITIONAL DASHBOARD/LEFT FRONT DOOR COUPLING | |||
| 5.There is engine knock | 1.Proceed as instructed in the fault diagnosis | |||
| 6.Error P0335 is present | 1.Proceed as instructed in the test | |||
| 7.Error P0606 is present | 1.Proceed as instructed in the test See Test 1060GK CONTROL UNIT SOFTWARE AND HARDWARE CHECK | |||
| 8.Error P1618 is present | 1.Proceed as instructed in the test See Test 1060GL CHECK ON OPERATION OF ENGINE MANAGEMENT CONTROL UNIT MAIN RELAY |
Parts & tools for this job For 2005 Fiat Croma
- TOOLDigital multimeterSearch: automotive digital multimeter
- PARTAssorted fuse kitSearch: car fuse assortment kit
- TOOLWire crimper and connector kitSearch: wire crimper connector kit
Links open Amazon search results in a new tab. As an Amazon Associate I earn from qualifying purchases.