Greg5OH

I see there is a thread from 2014 about a similar issue.
Ive had no problems with our 2011 GL550 in the last 3 years.
After sitting for about a week, went to go drive it-wouldn't crank, no gear position available.

Thing is, its an intermittent issue. sometimes can crank and move, other times not. Pulled it into the garage to start diag.

C4 scanner showed at the current time the following modules offline:
-ECM
-TCM
-SCM
-ESP
-SRS
and i know airmatic is going wonky too

Best part is...my china clone c4 died shortly after this...laptop won't connect to the interface..great

Initial thought- CAN issue, or a power supply/ground issue.
Most likley CAN as these modules have seperate power feeds and grounds.

I checked voltage on CAN hi and lo at the DLC (obd) port, both about 2.4V on it, ok thats fine, CGM is sending a signal out

I pulled back driver and passenger front carpets, no signs of water ever, CGM looked brand new.
Checked the X30 connectors in the passenger right kick panel and the lower glove box panel, look ok.
let it sit overnight.
This morning I was able to start it as apparantly the ECM and TCM are back online (shows gear position)

Next will be getting some voltage measurements from CAN B and C channels. waiting on some needle probes to come in tomorrow.

I'll keep this thread updated as I go, and post a resolution.
Will have a youtube video made up once I get this all squared away.

Max Blast

Interesting… Do you think the clone DAS parking the modules in an interrogated state and then dying may have bricked something? Also, everything you’re describing leading up to this event sounds like a voltage draw causing a dying battery. Did you check it?

eric_in_sd

Seconded. You are dealing with a bunch of computers connected to a battery. Even though it is the most mundane methodology, always check both alternator and battery health before proceeding.

Greg5OH

No dont think the star unit getting bricked affected the vehicle at all. All the symptoms that were there while i was plugging in were there after it died still.

regarding battery: that was my initial thought. 1 year old AGM. Verified it was at 12.1v sitting. Ive had it sitting hooked to a charger whole time, was hardly down on juice. Haven't load tested it but having a second battery and a charger all connected to it, and no errors for low voltage elsewhere, im unfortunately ruling it out as not the culprit.

Waspjr

I have seen something about the c4 clones batteries going bad inside iirc.

also I have similar thing going on and it was due to water.
have you looked in the trunk rear etc? Yet.

Max Blast

Just for your info, it’s entirely possible to stick the car in the ESP diagnostics mode semi permanently. If you don’t do the test, exactly, correct…it’s like an up up down down left right a b a b to get out of it.

Which means that the car is driving around and Dyno mode and giving all kinds of errors. So definitely look into whether the system remains in the interrogated mode.

if I also do recall correctly, I think all modules reside under their respective Sam or the central gateway… Someone smarter than me can check me on this, but if your gateway is bricked, that would prevent access to a whole Lotta things.

Greg5OH

Good to know about the diagnostic mode. Don't think im stuck in it as the symptoms are the same pre and post c4 scanner failure.
also good to know about the internal batteries. I haven't put batteries into it myself, but ill open it up and take a look.

The ECM TCM SRS etc run through the CGW, SAMs are on CAN B, these are on CAN C, ill have to double check the wiring diagrams. It could be the CGW is bad...visually it is ok, no water, or corrosion present. I know at least the CGW is communicating out to the DLC. but thats only 1 part of it.

I have to believe it is some kind of moisture problem somewhere on the CAN C network. we had 2-3 days of decent rain (had much worse before but...all it takes is 1 time..)
No water present anywhere in the cabin but there is a big connector at the right side under the HVAC box...hard to get into there to really see, let alone unclip the connecors. Will take some more dissasembly.

eric_in_sd

12.1V ?!?

I bought a "new" battery from Autozone. Inexplicably useless. I tested it for capacity - you can get electronic testers for about $10 - and it was at like 10%. Took it back to Autozone and they pointed at the sticker on the side, showing a manufacturing date about eighteen months in the past. If they don't keep the battery on a maintainer, it just turns to poo poo on the shelf.

Charging the battery, and putting another battery in parallel, is no guarantee.

You are dealing with computers on a battery and generator power supply. I recommend that before you proceed further, ensure both the battery and generator are performing to specification.

EmilyMB

I'm looking for CAN Bus and wiring diagrams for GL550 2010, please share.
TIA

Greg5OH

pm me your email ill send you a zip file with what i pulled for my vehicle

EmilyMB

Sent you my email. Thank you

Greg5OH

quick update
my C4 started working again...the error I was getting was no laptop to interface connection..but perhaps it really was to vehicle.
I inspected all underbody compartments front to back. No water, or previous signs of water, SAMs look good..so thats good.
The vehicle also is working just fine right now (at least starts and behaves normally in the garage, havent driven it yet)
I don't know if perhaps the connection was just a little loose at the CGW...plastic connectors were seated in their locks when i pulled it out...?
I tested the battery myself with my load tester and took it to AZ to be sure, both tests show the battery is in great health.

When I pulled it into the shop originally i DID see that the battery was 11.7V on the scanner...in which case totally possible that some module got below min spec voltage during an initiated crank attempt.
Ill try driving it next few days around town and see if it strands me.

I have two issues I need to take care of that I have known about, and now I may as well do it. Its not out of the realm of possibility that one or both of these caused a CAN issue as well.

1)Left blind spot monitor was intermittent for 6 months then the last 2 has been completely inoperative. Whole area is covered in mud, possible the seal is compromised and I need a new radar and/or wire harness there. However...I do not see any modules in the system scan that mention a fault for something related to a collision/lane/blind spot warning system?
2) for about a year now, when making a left turn, the wiper will do 1 sweep. Then it started happenning when making a right turn. Then last month or so, will do a random wipe when just driving..sun shining clear skies etc.

so, 2 permenant codes:
SAM-F: component or signal line to the component F58kB(Wiper ON/OFF relay) has a short circuit to ground
SAM-R: The output of component F4kR (Circuit 15R relay) has a short circuit to ground.

I shall report back after some probing on the two fault codes.

Greg5OH

That'll do it. Left blind spot radar module.
Water was starting to backfeed into the connector. Looks to have been recent as the pins have no corrosion.
Ordering up a good condition used one.

Greg5OH

FYI here is the video link to my complete diagnostic steps I took:

Greg5OH

New module installed. I have yet to road test it as I am waiting on a new front wheel bearing after FCP sent me the wrong one.

Greg5OH

^Update- everything works just fine. Blind spot assist works as intended, car starts reliably. No coding or anything else necessary, plug and play.

haitham600

Hello,
​Hello. I have a similar problem with CAN bus comm. It looks like all modules are not communicating. It looks like a water/moisture. It drained my new battery overnight. I charged the Battery and checked for water ingress. It looks like some water seeped in from the left tail light gasket. I dried it pulled the cables out and checked all connector look fine. Car started. Next day same issue, battery is not draining this time, in depth fuses checks for delta voltage. SRS EIS and intelligent Servo module are not communicating. Central gateway is healthy with no DTC detection.
SRS fuse in the right side panel of the trunk is pulling current from driver seat belt. Seatbelt is dry and normal. The automatic restraining function is gone from both front seatbelts.
car still not starting, I need the CAN communication diagram. This is going to be a nightmare.

Mdz

Kindly share can bus diagram and location for a GL550 X164

vesiadog

The module was for the left and right hand blind spots correct? The modules are located in the rear bumper correct? My GL550 blind spots will act up and stay on red sometimes ?? thanks Bill