7 replies to this topic

[kmidderigh]

Just got my car back from garage after service and having my Tullet silencer repacked.

 

Drives fine and on 30 minute drive home on busy A roads (all below 60 mph) everything was fine - but today went for a test drive on dual carriage way and when up to speed the engine warning light came on.

 

Checking this is showing following codes :

 

stored codes :

1. P0378

    Powertrain: Timing Reference High Resolution Signal B Intermittent/Erratic Pulses

pending codes :

1. P0778

    (added this description myself from internet lookup as listed as "unknown" when connected to car) Pressure Control Solenoid B Electrical

permanent codes :

none

 

However car seems to be driving fine - smooth and plenty of power (NA) - once light came on i drove home gently with no issues

 

I've searched and read all the posts on this topic - and wondered if any sensors would have been disconnected and then reconnected during the exhaust removal for repack - are there two on the exhaust?- could they have been put back the wrong way around ? might this cause this code ?

 

I've cleared the codes and reset the warning light - reading the description for P0378 it seems potentially quite serious but other post seem to suggest this is just a connector issue...

 

Is if safe to go for another test drive to see if it re-occurs or shouldn't i be driving it until issue understood and resolved ?

 

 

 

[smiley]

P0378 has been reported earlier when the post cat lambda was plugged back in the wrong connector.

 

 

Some late NA's have this extra (unneeded) connector in the loom.

 

If this fixes your problem, let us know, so we can add P0778 to our "known issues" database also.

Edited by smiley, 18 November 2017 - 06:29 PM.

[kmidderigh]

thanks for the info - can you get to this sensor from the top of the engine bay or is it an under the car job ?

[smiley]

You can try the top first.

Should be on the left side of the bay, all the way down to the subframe.

If that fails, you can also try from the bottom, or jack it up, remove left rear wheel, then the plastic wheel cover to do it from the side.

 

[kmidderigh]

ok - had a look around the engine bay this morning in the light and found a cable disconnected (as in photo where coolant tank is visible)

 

https://photos.app.g...xFtzrXd3oQbSe23

 

I've highlighted in yellow where it connects back to...

 

Now this cable is pretty short and theres only one maybe two places it could reach - the second photo shows these.

 

Looking at where the post cat sensor cable comes into the engine bay (yellow line at top of the picture) i think its got to be the connector with the white wires thats connected wrong ?

 

Anyone confirm before i try and swap them over ?

 

The only other option is the connector with the red arrow on it....? 

[Zoobeef]

The red arrow is the fuel cut off,

the one that's disconnected is the other lambda one spoken about above. So it may be that the wrong one of those is plugged in.

[vocky]

going by your second photo it's plugged into the early Lotus loom (chassis loom) rear lambda sensor plug

 

But you have the later Vauxhall engine loom, so it should go to the rear lambda sensor plug which comes from the engine (marked in yellow, first photo, near oil filler cap)

[kmidderigh]

great - thanks for the advice - disconnected existing connector with the white wires coming out the bottom and connected up the loose cable from the main loom.

 

- just come back from an hours thorough testing and all fine  -no engine light and car running lovely - result!