Fault code P0378 + other problems

[dewismotorsport]

Hi guys i'm new to the site, I'm struggling for help and info

Car: Mk4 astra coupe 2001
Engine: Z22SE

Ive had this fault code for a good while now, and tbh no one knows what it is or how to fix it, only symptom I had was a lumpy idle and would be a little sluggish to start, now I have changed the crankcase sensor and it made little improvement (genuine part from Autovaux)

I was driving down a dual carriageway and all of a sudden the following dash lights popped up:
Airbag
ABS
Coolent
Engine management light (already on)

And the power steering, radio stopped working and dash needles stuck at the same speed/revs as well as temp and fuel, car didnt want to idle so had to keep it at around 1000-1200k rpm so it didnt stall, once home the lights were only dim, windows wouldn't go up, the injectors were pulsing when engine off but ignition still on.

Checked all fuses and all seemed fine, wouldnt turn over, battery was dead so swapped for a spare and then all electrics worked as normal and would crank but seems like its not firing or fuelling one of the two, haven't got tools with me so can't check just yet ;-(

This is what the fault code itself says:
- Timing Reference Optical Sensor harness is open or shorted
- Timing Reference Optical Sensor circuit poor electrical connection
- Faulty Timing Reference Optical Sensor
- Damaged Powertrain Control Module (PCM)

The optical sensor provides a high resolution signal to the Powertrain Control Module (PCM) by counting pulses on the sensor disk located in the injection pump. The high resolution is one of the most important inputs by the PCM for fuel control and timing. This test monitors the number of high resolution pulses which have been missed (not detected). It's based on a comparison between the number of pulses that were detected since the last pump cam pulse and the number of the pulses that should have occurred. There are approximately 64 high resolution pulses for every cam pulse.

Now from what I've read it is to do with fuel and it's pump but others have stated to change cam sensor but after a call to Vauxhall they don't show a cam sensor or an optical sensor on there system so I'm at a loss tbh

Anyone had any experience of this or know any information?

Car has restarted on a different battery and drove as normal (lumpy idle still) but has drained it within a day, alternator belt is still present ;-)

Cheers Adam

 

[astra22bertoneauto]

Have you checked your alternator??? Ive had a couple go on me. 1 just gave me loss of power steering & battery light. Other 1 just made all the lights on the dash light up 1 after another (in no particular order) Then lights dimmed & needles stuck.

 

[dewismotorsport]

Have you checked your alternator??? Ive had a couple go on me. 1 just gave me loss of power steering & battery light. Other 1 just made all the lights on the dash light up 1 after another (in no particular order) Then lights dimmed & needles stuck.

Funny you should say that I've just come from outside testing it and it is indeed the alternator that's gone so gonna order a new one ;-) thanks for your reply

Still won't cure my P0378 fault code though so if anyone has any ideas on that one i'd be most appreciative

 

[astra22bertoneauto]

Have you checked the crank sensor?

 

[dewismotorsport]

Have you checked the crank sensor?

Yeah I replaced it about 8 months ago for a genuine one and made no difference to the fault code problems

 

[astra22bertoneauto]

While you are changing the alternator, whip your cam and chain covers off and check your timing. Maybe its slipped a tooth??? Also check your egr valve is not stuck open (if you have 1)

 

[dewismotorsport]

While you are changing the alternator, whip your cam and chain covers off and check your timing. Maybe its slipped a tooth??? Also check your egr valve is not stuck open (if you have 1)

Will check them thanks, was thinking of blanking the egr off but just never got road to it, have been thinking and maybe having a dying alternator it may have over time slowly dropped battery volts hence bringing fault codes up! Maybe once new alt is on and everything is getting powered as it should it may be ok, will wipe codes and see how it gets on, thanks for the help, I'm and xe/let man so all these sensors for sensors are a pain in the arse ;-)