MK5 Golf 1.6FSi rev limiting, cutting out. Please help

[Rpmayne 0]

Please help, my dad has a Golf 1.6 FSi on a 04 plate. Had a few problems recently with the fan overrunning after switching off for literally hours. Had to take the fan fuse out overnight to stop the battery going dead.

 

The EPC light was coming on, then this went on to the car seeming to limit itself to 4000 revs, then cutting out and not restarting. The local garage had it, a new ECU later (did show signs of water damage) and a bill of around £2000 it has started doing the same. Obviously a bit upset now, anyone got any ideas? I know this could probably be anything but we need to try something as the garage with the diagnostics couldn't find it and can't afford to spend anymore garage money on it.

 

Thanks for any help.

[floppyman 0]

For the fan problem you will need the whole fan assembly... Has for the engine problem, I would need to plug it in to diagnose... But these engines do have a problem with the high pressure fuel pump that gets worn out on the camshaft.... But like allways, best get it pluged in and let us know the faults

[floppyman 0]

For the fan problem you will need the whole fan assembly... Has for the engine problem, I would need to plug it in to diagnose... But these engines do have a problem with the high pressure fuel pump that gets worn out on the camshaft.... But like allways, best get it pluged in and let us know the faults

 

Has the fans been fixed by replacing the ecu? Whe the fan module misses communication with the engine ecu they will start spinning at full speed

[Rpmayne 0]

Cheers, I will try and get it to the garage to see what it says. Last time apparently near enough every code came up, hence they went for the ECU as being the fault.

 

This morning it started but the rev counter looked like it was loosing power, flicking from 1000k to nothing very fast without the engine speed actually changing. Then when pressing the accelerator nothing happened, seemed to be ignoring the accelerator position sensor. Turned off, restarted and the pedal would then work for a bit, then die again.

 

The engine light and EPC lights are both on.

 

Regarding the fan, it still overruns after the ECU has been changed.

 

Thanks.

[floppyman 0]

For the fans it will probably be the whole fan assenmbly.

Has for the rest, will need to know the fault codes.

[Rpmayne 0]

I have got VagCom which I have used (a long time ago) on the Corrado VR6, I haven't got the keys to check but do you know whether the connector is the same in the mk5 Golf? Thanks.

[floppyman 0]

I have got VagCom which I have used (a long time ago) on the Corrado VR6, I haven't got the keys to check but do you know whether the connector is the same in the mk5 Golf? Thanks.

 

Hum... Depends was the vr6 the two small plugs or a one big plug... If it was the big 16 pin plug then yes.... The same has the golf 5. Under the steering wheel near the pedals.

[Rpmayne 0]

Just tried it and after a lot of messing about I got some codes out. On the first run I got the following:

 

16500 - Engine coolant temp. sensor (G62): Implausible signal - intermittent

18354 - Control Module 1 for cooling fan, faulty

18041 - Accelerator position sensor 2 (G185): Signal too low - Lower limit exceeded

17440 - Sensor for NOx (G295): Signal too high - Upper limit exceeded - Intermittent

18322 - Pressure Sensor for Brake Boost (G294), Implausible Signal

18321 - Pressure Sensor for Brake Boost (G294), Short to Ground

17477 - NOx Sensor (G295) Heater control: Short to ground - Lower limit exceeded

16705 - Engine speed sensor (G28): Implausible signal

17796 - Internal Control Module drive by wire error; Control Module Malfunction - DBW Throttle Monitoring

 

After a codes reset I had the following:

 

18041 - Accelerator position sensor 2 (G185): Signal too low - Lower limit exceeded

17477 - NOx Sensor (G295) Heater control: Short to ground - Lower limit exceeded

18321 - Pressure Sensor for Brake Boost (G294), Short to Ground

16705 - Engine speed sensor (G28): Implausible signal

18322 - Pressure Sensor for Brake Boost (G294), Implausible Signal

 

Bearing in mind that the ECU has only been in for 2 weeks so no old codes, the first set is pretty alarming, and the second is not much better. Is it possible there is a common issue with some of these things. I'm going to see what the replacements cost now but it seems like a lot needs changing if its telling the truth.

 

Thanks.

[floppyman 0]

Can you give the engine code please?

[floppyman 0]

It might be a blf engine... You say there was some corrosion on the old ecu... Did they replace any pins on the plug? Cleaned them?

All of them faults ,excluding the fan module fault, are connected straight into the ecu... Example the accelarator possition sender (thats the trothle pedal) connects straight into the ecu, theres no extra live feed or ground.... So everything is pointing to the ecu.

If the ecu HAS been replaced, then maybe the connector is no good.... Or.... (I doubt) you need all of those sensors.

The only faults I think are sepparate from the ecu problem will be the coolant sensor and the fan module.... And maybe the brake booster (allmost all mk5 golfs 1.6 have that problem)

[Rpmayne 0]

Just had a look over the engine and the only label I can see stuck to the LHS of the head has a big barcode and the code BAG 066 062. Does that sound right?

 

I went out armed with a tooth brush and WD40 but the weather is rubbish so will try cleaning it later on. Looks pretty tight, take it you can't take the connector off without removing the ECU first.

[floppyman 0]

You have to take the wipers out and the scuttle tray (the black cover by the windscreen)

[floppyman 0]

Theres two plugs in the ecu... One of them you can take out with the ecu in place... The other one is better if you take the ecu out...

All the sensors go to the bigger plug, only the engine speed sensor goes to the smaller one, so check both plugs..... And.... Make shure it is a new ecu.