multiple trouble codes - re-starting old thread

[twa231inCA]

Greeting.
Restarting old thread related to multitude of trouble codes on LR3.
Majority are communication codes, and couple are more on sensor/O2
I'm new to LR3, knowingly got in to chasing gremlins:-)
CKP new (Bosch, old was unknown) no change, new alternator. That is pretty much all.
Wiring/harness integrity check, majority of grounds check. Battery good.

any suggestions what to do/check next?
I don't have GAP, using Launch scanner with enhanced LR diagnostic. Nothing like proper tool. Hoping that Santa may get me one soon.

ATCM-
U0402-94/T; Invalid data received from Transmission Control Module
U0416-94/T; Invalid data received from Vehicle Dynamics Control Module
IPC-
U0010-88/T; Medium Speed CAN communications Bus
PBM-
U0100-87/Int; Lost Communication Engine Control Module/Powertrain Control Module 'A',
U0101-87/Int; Lost Communication with Transmission Control Module,
PCM-
P0335-92/T; Crankshaft Position Sensor 'A' Circuit;
RLM-
U0416-86/T; Invalid data received from Transmission Control Module/Powertrain Control Module;
U0401-86/T; Invalid data received from Engine Control module/Powertrain Control Module;
TCM-
U2023-88/T; Fault Received from External Node
U0401-86/T; 'As Above'
VDM-
U0401-68/Hist; Invalid data received from Engine Control Module/Powertrain Control Module

[BradC]

Concentrate on the code you highlighted. The remainder 'U' codes are all communication related and could well be collateral damage. Often when dropping into a limp or failsafe mode an ECU will stop or slow communications on the bus causing faults in all downstream modules.

I have no real info on the CPS on Petrol engines other than the service manual. On the V8 it can be replaced from under the car. On the V6 apparently the exhaust system has to be removed first.

P0335 is a bit of a rash all over the internet, but there's not a lot of landrover specific hits.

[101RRS]

Clear all the codes and on restart see what comes back - these will be the important ones.

[twa231inCA]

CKP on V6 is accessible from left hand after removal of battery try and heat shield. Kinda working in the dark. 30 min task.
No need to touch manifold (similar to starter replacement, more tricky still durable without removing ex manifold.
Back to main issue - clearing codes is good for few starts and they're back.
First to pop-up is the CKP. Since CKP is directly connected with two wires, basic check (CKP to ECM) all good.

[twa231inCA]

I noticed correlation between certain events to errors:
In many (not all, would say 25%) of cases when starter is running, there's a split second pause in starter operation. Engine fires up every time. With or without that hiccup.
When I have hiccup, transmission error always comes up. Simple restarting clears transmission errors - MIL stays ON with 0335-98. According to alldata that error indicates CKP voltage >=8V (below or eq).
Min/max voltage check on startup (battery terminals) shows min 10.1V, max 14.1V. Means battery voltage is not dropping below 8. Since i don't have Pico or other tool to have cont reading/graph, I can only rely on my multi-meter max/min. Starting to lean towards electricity supply/possibly relay issues in main fuse box (visual on fuse box all clear).

[LuckyLes]

Even 10.1 is too low. Starter battery should not drop below 11v when starting. Any lower and the battery should be replaced. In a Landrover, a poor battery will show up all sorts of faults.

[Eric SDV6SE]

Yes, your battery appears to be impersonating a boat anchor.

[twa231inCA]

Yes, your battery appears to be impersonating a boat anchor.

According to specification, battery voltage "resting" should be 12.4-12.6V. My shows 12.65V.
May I ask why you're assuming that battery is not good? Because my multimeter recorded 10.1 on cranking?
I tested on Toyota and Subaru in household - getting even lower values (Sequoia down to 9.9V on crank).
There's no impact on anything...
thanks!

[Graeme]

How low does the voltage go during cranking if the headlights are on? The battery could be low on reserve capacity and the voltage dropping lower than what the LR modules require.

[Eric SDV6SE]

Resting or float voltage may appear OK, but when starting if the volts drop to around 10v or below, there's not enough current capacity and the LR's systems report a fault. A multimeter is also not as good as a carbon pile load test, but gives you an idea at least. Before dropping in a new battery, put it on a charger for a few hours.