Danger | Risk of death when working on component parts and systems with U >= 30 V alternating voltage (AC) or U >= 60 V direct voltage (DC) | Do not touch damaged or defective live component parts and lines or non-insulated electrical connections and lines. | |
Danger | Risk of explosion caused by fuel igniting, risk of poisoning caused by inhaling and swallowing fuel as well as risk of injury to eyes and skin caused by contactwith fuel. | No fires, sparks, open flames or smoking. Pour fuels into suitable and appropriately marked containers only. | |
Topical note | Notes on avoiding damage to ignition system | ||
Connecting hand-held tester (HHT), reading fault memory | |||
Gasoline injection and ignition system (ME-SFI) - Diagnosis - Previous knowledge | |||
Troubleshooting | |||
Complaint | Possible cause | Notes | Remedy |
Engine starts reluctantly and is reluctant to speed up | Fuel injection valve actuation and injection duration | ||
Spark plugs | |||
Eliminate unmetered air | |||
Engine fails to start | Power supply missing | ||
Check compression pressure/oil pressure | |||
Ignition voltage too low | |||
Spark plugs | |||
Engine has rough idling | Camshaft timing | ||
Eliminate unmetered air | |||
Poor engine output | Catalytic converter flow rate too low | Check exhaust gas back pressure, see engine DMAN, reg. A "engine output" | |
Engine running rough (vibrating) | Fuel injection valve actuation and injection duration | ||
Spark plugs, ignition coils | |||
Check compression pressure | |||
Eliminate unmetered air | |||
Engine running rough (misfire) | Ignition voltage too low | ||
Spark plugs | |||
Engine surging after cold start | Unmetered air | Eliminate unmetered air | |
Transition fault during warm-up | Coolant temperature sensor (B60) | ||
Eliminate unmetered air | |||
Transition fault; warm/ poor fuel economy | O 2 sensor upstream of catalytic converter (R22) | ||
Engine jolting | Hot-film MAF sensor (B41 ) | ||
Spark plugs | |||
O 2 sensor upstream of catalytic converter (R22) | |||
Electronic accelerator is in limp-home function | Set value potentiometer in pedal value sensor | ||
Referenced documents
- ad0000s200003a Connecting Hand-Held Tester (HHT), reading fault memory
- ad0761s2000a Gasoline injection and ignition system (ME-SFI) - Diagnosis - Previous knowledge
- ah1510p000201d Notes on avoiding damage to ignition system
- as0000z003501a Risk of death when working on component parts and systems with U >= 30 V alternating voltage (AC) or U >= 60 V direct voltage (DC)
- as4700z000101a Risk of explosion caused by fuel igniting, risk of poisoning caused by inhaling and swallowing fuel as well as risk of injury to eyes and skin caused by contactwith fuel.