Electrical faults after D4 3.0 body R&R

[Graeme]

Lots of HS canbus faults suggesting OC somewhere, with wiring from ECM to TCCM/TCM/ABS still to be fully checked. TCM has 2 copies of HS canbus with 1 pair open circuit somewhere, have yet to recheck continuity from ECM connector to TCM connector once the D4 comes back to my place but bridging the 2 canbus circuits didn't change anything. Instrument cluster doesn't operate if the TCCM is unplugged. ECM connector that has the HS canbus wires was not disturbed in the body R&R, only the other ECM connector (engine harness) unplugged to stay with the engine. No bent pins in the ECM socket. Diagnostic socket has direct connections to the ECM and TCM so doesn't require access via the HS canbus to retrieve comms faults from those modules.

Engine has run twice sounding good, topped-up coolant and general checking but wouldn't restart until left for a few hours but now won't restart. Instrument cluster powers-off when attempting to start but no noise from the starter motor solenoid. Suspect a ground issue but mechanic rechecked body to engine cable. A detailed check will commence once the vehicle is back with me.

Looking for suggestions as to what may have been left disconnected or anything simple to be checked before getting into the detailed checking.
Thanks.

NB The original engine harness was fitted to the replacement engine before the body was refitted.

[DiscoJeffster]

About the only thing I can add is the rear large connector is known to be an issue and I recall pins can get pushed out when reconnecting. Some past canbus issues have been resolved there. Good luck. I hate troubleshooting those types of issues.

[Graeme]

Are you referring to the ECM connector that has to be unplugged?

[DiscoJeffster]

Are you referring to the ECM connector that has to be unplugged?

At the rear of the vehicle (LHS, near the left hand bag I recall, on the frame) is a large multi-pin connector. There have been posts prior where this connector has been an issue for body off.

[Graeme]

Thanks lots. Might have to see if the car is still on the hoist in the morning.
I'll see if I can find it in the wiring diagram.

[Graeme]

The park brake module contains the HS canbus far end terminating resistor. If that connector hasn't been fitted than comms faults will occur even if some data can get through. A definite contender!

[Graeme]

The connector had been fitted but this morning R&R'd to check pins and reseat, but no change.
Gbox harness has solder joints for the 2 sets of HS canbus so the body side connector only has to supply 1 side although wiring diagram shows both from ECM via different solder joints, so more ECM to gbox plug is required.

[Pierre]

Graeme, many find that the two connectors on the rear left hand rail randomly break conductors, so worth a check. The plug on the EPB loom is also a candidate for that behaviour. We are just troubleshooting our 08 RRS with the same sorts of issues, one of which was a self-bricked TCCM!!

Good luck with troubleshoot. I am watching with interest.

Pete

[Graeme]

Thanks Pete for your suggestions.

The workshop owner today returned from holidays. The mechanic has asked to keep the car 1 more day, presumably to work through with the workshop owner who most likely wouldn't be wanting to return the car not running.
I'll give that connection a thorough check if the faults are unresolved, after first checking the resistance between the 2 bus wires to ascertain if the bus is intact or not.

The TCCM from my L322, an identical part but might have different software, was tried last Thursday with no improvement.

[Airmech953]

I had similar problems on my 05 Disco. The fault was eventually traced to a crushed canbus wire at the rear nearside connector (behind the wheel). Continuity checks were ok but when the individual wires were given a shake test, then the faults could be replicated. A new 6 inch length of canbus wire and connector pin fixed the problem for me.

[Graeme]

The mechanics gave-up in favour of my son and I seeing what we can do.

The HS canbus end to end integrity is OK by a resistance check so now concentrating on ecm power and grounds. The brake switch was reset in case it had been upset but still not starting, noting that the brake pedal is very high and hard. The switching off when attempting to start could just be switching off in the absence of the OK brake fluid pressure signal from ABS because the canbus is inoperative, so that issue is being ignored for the moment. However brake switch operation is still to be checked using the IIDtool.

[Graeme]

The ABS module doesn't feature in the list of ecus. Power is at the FL & fuses which are OK.

[discorevy]

I'd expect it has already been checked, but sometimes the simple things...

Is the battery ok and is the brake pedal being stepped on hard enough to set the brake switch now that there is no vacuum assist?

[Graeme]

Yes, I'm looking/hoping for something simple. However battery voltage is fine and the brake switch was R&R'd to reset it. Upon wanting to check the switch status using the IIDtool in case the pedal is too hard to press down enough, there was no sign of the ABS module then again no sign for ecu s/w level status. I had earlier noticed that the HDC switch didn't provoke any response. The diagnostic port K line goes to the ABS module so if the ABS module is functioning then I would expect the ABS module would have comms faults for the other modules which are reporting comms faults with the ABS module, but there aren't any.
Next check is for power and ground at the ABS connector.

I'm still pondering why the suspension raise and lower switches are both reported as on, which means that the voltage on both those signal wires is below the threshold for being considered off. The 2 wires connect to the suspension ecu via different plugs but presumably run in the same harness until close to the suspension ecu.

[Graeme]

The 2 ABS connector ground pins continuity between each other but OC to body - almost there I feel.

Power and ign OK.

[Graeme]

The nut from the earth stud was missing. The mechanic had disconnected the winch earth cable from the stud leaving the other terminals unclamped. Now no coms faults although it didn't start with only just the aux battery which is getting low. Might still be something else to be resolved.

[PerthDisco]

The nut from the earth stud was missing. The mechanic had disconnected the winch earth cable from the stud leaving the other terminals unclamped. Now no coms faults although it didn't start with only just the aux battery which is getting low. Might still be something else to be resolved.

Always the most frustratingly simple thing as usual. Well done

[Graeme]

Now to get the power steering pump to work and to sort out why the suspension raise and lower switches don't work. I thought that maybe the reservoir's filter was blocked so ordered a new reservoir, only to discover that the filter looks spotless with most of the fluid having been removed. I'm now wondering if the mechanic or his apprentice left a cloth plug in the pump inlet as the pump seems to be cavitating with no fluild being returned to the reservoir.

[Pierre]

Graeme, eventually a simple, if partial, solution. Earths, eh? Who'd have thought?

Well played.

Pete

[Graeme]

Another issue resolved. Suspension system diagnostics showed just over 1V on the main 12V supply. The 20A fuse was missing. I had wondered from where the 20A fuse in the console had come so now I knew, but I had forgotten that it was I who had removed the fuse to prevent any further possible lowering whilst on the trailer to the mechanics.
1 issue to go...

[PerthDisco]

Another issue resolved. Suspension system diagnostics showed just over 1V on the main 12V supply. The 20A fuse was missing. I had wondered from where the 20A fuse in the console had come so now I knew, but I had forgotten that it was I who had removed the fuse to prevent any further possible lowering whilst on the trailer to the mechanics.
1 issue to go...

Explains switch not working

[Graeme]

The lack of power steering seems to have resolved itself, mostly anyway. No assist still on 1st start this morning but then there was. I suspect a sticky valve plunger due to dirt ingress causing minimum displacement but hoping that the contamination is now caught in the filter in the bottom of the reservoir.

A new issue has occured. It appears that the turbine control valve on the replacement engine, the one on the exhaust side of the secondary turbo, has to be calibrated, which means that the ECM has to learn the closed position which varies from valve to valve. Restricted performance occurs shortly after engine start but not if the throttle is pressed soon enough to cause the valve to open, but RP then occurs as soon as the throttle is released. Live values shows the valve position at approximately the commanded position when the engine is above idle but there is a discrepancy at idle which triggers 2 DTC indicating that the valve is stuck.
The IIDtool doesn't appear to provide turbine control calibration function. A question for Gap.

PS No valve calibration for my 4.4 TDV8 either, not that it needs it atm.

[DiscoJeffster]

The lack of power steering seems to have resolved itself, mostly anyway. No assist still on 1st start this morning but then there was. I suspect a sticky valve plunger due to dirt ingress but hoping that the contamination is now caught in the filter in the bottom of the reservoir.

A new issue has occured. It appears that the turbine control valve on the replacement engine, the one on the exhaust side of the secondary turbo, has to be calibrated, which means that the ECM has to learn the closed position which varies from valve to valve. Restricted performance occurs shortly after engine start but not if the throttle is pressed soon enough to cause the valve to open, but RP then occurs as soon as the throttle is released. Live values shows the valve position at approximately the commanded position when the engine is above idle but there is a discrepancy at idle which triggers 2 DTC indicating that the valve is stuck.
The IIDtool doesn't appear to provide turbine control calibration function. A question for Gap.

Mate, what a ball-ache. You’re venturing into areas few go. Godspeed!

[shack]

Shouldn't the stepper motor "self learn" position zero?

Do they cycle through on each start?

I'm not aware what the 3L turbos are, but most VNT's have a set screw to set the "vane closed" position, I would have thought the stepper would learn this on a cycle through, it can't adjust the stop/closed position itself.

Again, I don't know much about it at all, but that seems logical.


Edit: Been searching online for an answer to this with no success, I hope you get it all sorted out soon, I imagine it's getting frustrating!

I think you've done a great job with what you've done, especially the new bearing type, I'm really interested to see how it goes, hopefully well !!

[Graeme]

It's the exhaust shut-off valve on the back of the secondary (fixed) turbo. The valve operates by vacuum controlled by a solenoid at the front of the engine. The valve's position is monitored but the closed reading doesn't match this ECM's recorded closed reading.
My son has sent a question to Gap.

[shack]

It's the exhaust shut-off valve on the back of the secondary (fixed) turbo. The valve operates by vacuum controlled by a solenoid at the front of the engine. The valve's position is monitored but the closed reading doesn't match this ECM's recorded closed reading.
My son has sent a question to Gap.My bad, I misunderstood..

[Graeme]

Lots of learning all round...

Gap have requested the DTCs.

[Graeme]

It transpires that Gap recently added the 3.0 D4 ECM turbine calibration to the G3 tool but won't add it to the G2, advising instead to sell the G2 and buy a G3. That's not going to happen.

Anyone in the Wagga area with a G3 to see if it will do the calibration without being registered to the D4?

My G2 reads and clears at least some faults on my MY21.5 L405 but needs a G4 to make CCF changes. A G4 with a modified cable will work with the D4 but might not do the turbine calibration without being registered to the D4, but at over $1100 for a G4 I'm not about to rush out and buy one anyway.

[shack]

It transpires that Gap recently added the 3.0 D4 ECM turbine calibration to the G3 tool but won't add it to the G2, advising instead to sell the G2 and buy a G3. That's not going to happen.

Anyone in the Wagga area with a G3 to see if it will do the calibration without being registered to the D4?

My G2 reads and clears at least some faults on my MY21.5 L405 but needs a G4 to make CCF changes. A G4 with a modified cable will work with the D4 but might not do the turbine calibration without being registered to the D4, but at over $1100 for a G4 I'm not about to rush out and buy one anyway.If you find someone with a G3, it's "only" $165 to unlock one extra VIN, I'd be positive it won't work without doing that.

[DiscoJeffster]

It transpires that Gap recently added the 3.0 D4 ECM turbine calibration to the G3 tool but won't add it to the G2, advising instead to sell the G2 and buy a G3. That's not going to happen.

Anyone in the Wagga area with a G3 to see if it will do the calibration without being registered to the D4?

My G2 reads and clears at least some faults on my MY21.5 L405 but needs a G4 to make CCF changes. A G4 with a modified cable will work with the D4 but might not do the turbine calibration without being registered to the D4, but at over $1100 for a G4 I'm not about to rush out and buy one anyway.

You could probably buy one and resell the old one for minimal changeover. [emoji2373]

[BradC]

You could probably buy one and resell the old one for minimal changeover. [emoji2373]

I often see GAP tools being sold second hand for nearly what a new one is worth direct from GAP, so I'd believe it.

[Graeme]

I've asked BlackBox if my old MSV-2 will do it if it was changed back to the D4, but suspect not.

[Eric SDV6SE]

I still have my Blackbox Rovacon VCIQ thingy, car is long gone.. PM me and we can sort something out I'm sure.

[Graeme]

Thanks Eric for the offer to help.

I'll probably buy a G4 IIDtool that I most likely would have eventually bought for my L405, to use initially on the D4 to do the turbine ECM calibration then transfer the G4 to my L405 at minimal cost. The G2 that is currently licensed to the D4 can then stay with the D4. My son has contacted Gap to check that the G4 is programmed to do the calibration, being mindful that 2 wires in the diagnostic connector have to be removed for the G4 to work with the D4 at all.

Also I need to have confirmed that the G4 will set my L405's stop-start switch on start-up to as-last-used rather than on and that the G4 can disable the automatic park brake engagement when Park is selected, which currently are the only reasons for wanting a G4 as my G2 reads and clears the L405's faults. I tried my L405 without MHEV operating to prevent stop-start, but didn't like the reduced engine braking, poorer off the mark smoothness and increased fuel consumption so have returned to switching off stop-start on start-up.

PS I still have my MSV-2 Extreme but the PC software doesn't support turbine calibration and the software hasn't been updated by BB for many years, so no chance of using that.