Engine Management light on VW Golf 1.6L 2000

Marvin

• 85242 Answers
• Posted on Sep 02, 2008

SOURCE: ECU engine management warning light

There is a problem, it needs to go to a factory service center, it can be any one of multiple reasons that turns this light on.

SOURCE: emission warning light

diagnostic check other wise you are just guesstimating!!

Jeffrey Turcotte

• 8991 Answers
• Posted on Oct 13, 2010

SOURCE: engine management light stays on garage said it

It is usually the catalytic converter, but sometimes it is the oxygen sensor. If you have an volt/ohmmeter, you can check the sensor. Unfortunately I cannot access your wiring diagram, so I cannot tell you which terminals are which on the sensor. There are 4 pins in the plug. Check 2 at a time for resistance. When you find 2 that have a resistance of about 2-5 ohms, those are the heater terminals. Your sensor heater seems to be working. So, then you want to check the voltage on the other 2 terminals while someone revs the engine up and down. If you have more questions, please let me know. Here are testing instructions from autozone.com:

1. Disconnect the Heated Oxygen Sensor (HO2S). Measure resistance between PWR and GND (heater) terminals of the sensor.
2. With the engine hot-to-warm, the resistance should be 5-30 ohms.
3. At room temperature, the resistance should be 2-5 ohms. If the readings are within specification, the sensor's heater element is okay.
4. With the O2S connected and engine running, measure voltage with a DVOM by backprobing the SIG RTN wire of the oxygen sensor connector. The voltage readings at idle should stay below 1 volt. When the speed is increased or decreased, the voltage should fluctuate between 0 and 1 volt; if so, the sensor is okay.
   

SOURCE: VW Golf m4 gti had both

HAVE VECHICLE CODE SCAN COULD HAVE ECM PROBLEMS, IF YOU HAD OLD TROUBLE CODES ERASED AFTER THE REPAIR WAS DONE PROBLEM COULD BE IN ECM.