Posts Tagged ‘ Astra H Electrical Issues ’

Electrical Gremlins Part Two!

Well it would appear that the electrical gremlins have reappeared; the moment the car pulled out of the pit garage at Snetterton at the last track day!

With previous checks on the other electrical units carried out, the next logical place to look had to be the instrument pack, as this was still playing up. Vauxhall charge a retail price of £346 + VAT for a brand new instrument cluster. Having done yet more research it appears that a fault of some sort within the instrument cluster can cause the issues that have been experiencing.

Common faults with instrument clusters can manifest themselves as follows:

  • Background illumination failure.
  • LCD has pixels missing or is completely blank.
  • Warning lights flickering or dim.
  • Gauges flicker till vehicle warm.
  • Intermittently vehicle does not start.
  • Intermittent loss of power to the complete instrument cluster.
  • Complete power failure to instrument cluster.

Now whilst I do not have all of the symptoms, certainly six of the above faults have been evident.

Removing the instrument cluster is pretty straight forward, once the upper and lower cowls are lifted clear the instrument cluster is held in place by 2 x T20 torx screws accessible at the bottom of the cluster; one each side. The cluster can then be removed from the bottom and once the multi plug is removed the cluster can be carefully lifted clear.

The cluster was then sent away for inspection and specialist repair. It was confirmed that there were a couple of issues with the circuit board(s), so these were repaired and the unit returned in a couple of weeks ready to fit, complete with a 2 year warranty on the repair work that had been carried out.

Fitting and programming the instruments (IPC) back into the car the expected result was ‘instrument panel functioning normally.’ Sadly this was not the case and the instrument needles dropped out as soon as the engine was started and the lights flickered!

So back to square one almost, and start again.

Thinking there was still an issue with the repaired instrument pack (IPC) the repaired cluster was then tried in another car; a car which had no other known issues. The repaired cluster functioned perfectly. So there was clearly no issue with the repaired IPC.

So another known working instrument cluster from another car was tried, but this played up as soon as it had been programmed and the car started. So the problem was clearly somewhere in the car.

The DTC’s remaining at this point were now just three:
U2100 IPC No Communication CANBUS Low Speed.
U2140 REC CANBUS No Communication with IPC
U2116 REC CANBUS No Communication with UEC

which was an improvement from when this first began as every conceivable DTC was present indicating lack of communication between everything electrical! UEC, REC, IPC, CIM…..

Looking at the DTC’s it suggested an issue in the REC.

Time to recheck the other electrical control units again……

Unplugged the stereo, just in case it was causing an issue. No change.

Try another known good headlight switch, because in the past the lights had been coming on randomly. No change.

A known good Rear Electrical Centre (REC) fitted and programmed. Still issues with the IPC.

A known good Underhood Electrical Centre (UEC) fitted and programmed. Still issues with the IPC.

The UEC that was tried had no fuses or relays in it, these had to be swapped across from the existing unit, so in case the issue was with one of these items another known working UEC was swapped across. All the pins and terminals were cleaned with electrical contact cleaner, and a coat of Ultra2040 water repellant (just in case) applied to the terminals in the wiring loom. Again no change, IPC still playing up.

REC multi plugs removed and cleaned with contact cleaner and refitted. No change.

So time to start checking earths……

Checked the 3 earth points next to the UEC. No change.

Removed the REC (again!), to gain access to an earth point behind the L/H/S quarter panel trim. The retaining nut unscrewed by hand….. so it was removed and the earth point and the retaining nut were cleaned with some 800 grit paper. The two earth wires were refitted and secured by the retaining nut.

Battery reconnected and engine started….. IPC functioning correctly.

So then it was just a case of swapping the REC back to the original one, the UEC back to the original one with the original fuses and relays and finally the IPC. After each individual unit was swapped back the car was started to check no issues had reappeared.

So chasing trouble codes turned out to be a slightly loose earth on the REC.

Note: Each time any electrical unit was removed the battery was disconnected prior to removal to prevent any current surges which could damage any electrics.

Astra H Electrical Gremlins.

Towards the end of last year, occasionally at start up the dials would drop out and then do their ‘VXR’ reset sweep and various dash lights would come on. Then once it had ‘reset’ itself everything was fine. Also from time to time the car would not turnover, not recognising the key, and so would not start. It didn’t cause any issues but was something that would need further investigation at some point.

That point has arrived with the instrument panel now resembling Blackpool Illuminations almost all of the time…..

Various dash lights illuminating either at random or all at once, rev counter dropping out and then carrying out the ‘VXR’ reset sweep and returning to normal opration, fuel gauge dropping to empty, headlights coming on with the headlight switch in the ‘off’ position, headlights coming on as expected when switch on but then failing to go off when the switch was turned off, rear lights coming on at random, indicators sometimes refusing to work……. Additionally sometimes the car would fail to start and the management light would flash, indicating an immobiliser problem which is part of the CIM module.

A quick check on Tech 2 listed many communication errors between all of the modules on the car (see post below for DTC’s) – CIM (Column Integrated Module), REC (Rear Electrical Centre), UEC (Underhood Electrical Centre), ABS/ESP (Anti-Lock Brake and Electronic Stability Module), and ISP (Instruments) which meant tracing the problem would be down to systematically checking the common error codes on TIS and working through and checking each module to eliminate them one by one.

Where to start?

Initial thoughts…. It was the CIM playing up, not uncommon on Astra H. While swapping one isn’t that difficult to do, it is quite involved so due to all the trouble codes it was worth checking the other modules first.

UEC: Water Ingress in the UEC can cause issues, but after unplugging and checking this was all ok, so the contacts were given a clean and grease to prevent any future problems.

REC: There were few DTC’s relating to lack of communication between the REC and UEC, REC and CIM and REC and ABS/ESP. The REC is easy to change as there are only 6 electrical plugs to remove and a single bolt holding it into the car. I had a spare REC to hand so it was worth trying it to eliminate it. The original REC was reset on Tech 2, battery disconnected and then removed and the replacement REC fitted. The replacement REC I had was from a later 2008 car but compatible as it was in the same ident range. The new REC was programmed on Tech 2, VIN entered and coded and all worked fine, however after some testing the same DTCs were present suggesting that the problem lay elsewhere.

CIM: As stated earlier the CIM units are known to cause issues, so having looked at the UEC and REC the next option was to try a replacement CIM module. The occasional loss of communication between key and CIM suggesting an immobiliser issue pointed strongly towards the CIM unit as well. Slightly more involved to replace unlike the REC and UEC as the airbag and steering wheel have to be removed to access the CIM and it needs resetting prior to removal and reprogramming again (using Tech2 or similar), but I had a spare second hand CIM to try so it was swapped onto the car, and after reprogramming all the troublesome DTCs had gone and the instruments appeared to be functioning normally.

A brand new CIM unit has been ordered (thankfully they are not too expensive at trade price!) and will be swapped over before the first track day.

Electrical Issues – DTCs

With the instruments doing really weird things (see post above) these were the trouble codes read by Tech2:

Stored in DIS – Info Display:
U2141 Can Bus No Communication with REC
U2140 Can Bus No Communication with UEC
U2100 No Communication with Can Bus Low Speed

Stored in REC – Rear Electrical Center:
U2140 Can Bus No Communication with UEC
U2116 Can Bus No Communication with IPC
U2113 Can Bus No Communication with SDM
U2100 No Communication with Can Bus Low Speed
B3089 Pane Breakage Sensor Rear Window Heater Circuit Open or High Voltage
B1375 Switched System Voltage (Ignition On) Not Plausible With CAN Signal
B0655 Brake Light Switch Circuit Incorrect Signal
B3916 Alarm Siren Battery Voltage Low

Stored in UEC – Underhood Electrical Center:
U2141 Can Bus No Communication with REC
U2139 Can Bus No Communication with CIM
U2116 Can Bus No Communication with IPC
U2100 No Communication with Can Bus Low Speed
B1375 Switched System Voltage (Ignition On) Not Plausible With CAN Signal

Stored in IPC – Instrument Panel:
U2139 Can Bus No Communication with CIM
U2140 Can Bus No Communication with UEC
U2141 Can Bus No Communication with REC
U2100 No Communication with Can Bus Low Speed
P0460 Fuel Level Sensor Circuit Range/Performance
P0115 Engine Coolant Temperature Signal Range/Performance
P0654 Engine Speed Signal Range/Performance
P0500 Vehicle Speed Signal Range/Performance
P0550 Mileage Circuit Range Performance

Stored in CIM – Column Integrated Module:
U2141 Can Bus No Communication with REC
U2140 Can Bus No Communication with UEC
U2116 Can Bus No Communication with IPC
U2100 No Communication with Can Bus Low Speed
B3977 Wrong Environment Identifier Received UEC
B3929 Wrong Environment Identifier Received REC
B3925 Wrong Environment Identifier Received IPC

Stored in Engine ECU:
P1616 CIM Wrong Environment Identifier
P1614 Wrong Transponder Key
P0136 No Plausibility between O2 Sensor Bank 1 Sensor 1 and O2 Sensor Bank 1 Sensor 2

Stored in CDC (Computer Damping Control) which has been disabled:
C0000 Damper Mode Switch Info Via CAN BUS Incorrect Signal

Astra VXR Sprint.....

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