[SOLVED] Service Suspension after Rear Shock change

[tengelman]

Hello everyone!

Today I changed the rear shocks of my 2013 Cadillac Escalade Hybrid. The old shocks were "blown".
I did this like it is shown here:

Now the dash display says "Service suspension".
The OBD shows two errors in the EBCM:
- C0045-04
- C0050-04

The MIL doesnt light up and the Truck runs great with the new shocks.
Just this message....

Any ideas?


Regards
Dennis

 

[Joseph Garcia]

I assume that your rear shocks are the ones that have both air and electrical connectors. Your errors indicate that the electrical circuits to both rear shocks are not operational.

First, when you start the truck after several hours of being off, do you hear the rear air compressor fire up for about 5-6 seconds? If not, your compressor may not be working, a common issue, when the shocks fail. The compressor literally burns itself out trying to fill leaking air bladders. So start there if you don't hear the air compressor fire up. Check the air compressor fuse in the fuse box. If the fuse is good, pull out the compressor (easy to do) and put 12 volts directly on the compressor power feed wire. If the compressor does not fire up, then replace it.

If the air compressor does fire up, squeeze the air bladders on the shocks afterward to see if they are firm, meaning that they have air pressure inside of them.

If all is good above, then check the electrical connectors on the shocks to ensure that they are firmly connected. If good, then check the electrical connectors above and a bit behind the top of the shock, on top of the frame. These connectors often get disconnected (inadvertently) when changing the rear shocks.

Let us know what you find.

 

[tengelman]

Thank you!!

I assume that your rear shocks are the ones that have both air and electrical connectors.
Yes!

I havent heard the compressor for a loooong time. So thats the spot to start. I will check next weekend.
But I am confused:
As the compressor might be out of work for a longer time I NEVER had "Service suspension" on the display with the old shocks.
How could that be?
(The air bladders of the old shocks were competely blown or at least torn away)

 

[SpareParts]

If there is no air in the air shocks, That's a bad thing! I would not drive with new shocks and no air pump.
Don't know if anyone realizes it or not.
With no air the rubber bladder will rub against itself on the inside part creating friction, heat and wear causing damage to the rubber bladder on the inside.
I believe that is why the compressor comes on for a few seconds after startup to make sure the bladder is partially inflated.

 

[tengelman]

update:
(came home from work earlier today)
So I checked the fuses, the wiring, connectors and the compressor.
Result: compressor is gone

I just ordered a new one. Will keep you up to date when I have it installed!

But it still confuses me, that the "service suspension"-message did not came on with the old shocks...

 

[swathdiver]

update:
(came home from work earlier today)
So I checked the fuses, the wiring, connectors and the compressor.
Result: compressor is gone

I just ordered a new one. Will keep you up to date when I have it installed!

But it still confuses me, that the "service suspension"-message did not came on with the old shocks...

There's probably a reason, can you pull the suspension and BCM codes?

 

[tengelman]

When I take a look at the old shocks....the compressor might had a lot of work

...and here is what my OBD says:

 

[tengelman]

UPDATE:
Changed the compressor yesterday. Quite an easy job. About 30 Minutes.
I can hear the compressor working and I think the ride is smoother now.
So far so good, but the "Service Suspension System" still appears at the dash....What can I do?

 

[Joseph Garcia]

Did you check/confirm this?

'If all is good above, then check the electrical connectors on the shocks to ensure that they are firmly connected. If good, then check the electrical connectors above and a bit behind the top of the shock, on top of the frame. These connectors often get disconnected (inadvertently) when changing the rear shocks.'

 

[tengelman]

Yes. I checked those before I changed the compressor. The connectors above the frame were disconnected (accidentially). When they were disconnected I had a lot of messages on the dash (ABS, Tire Pressure, Traction Control....).
These little connectors seem to destroy everything

After that I only had the "Suspension"-Message - which is still there after installing the new compressor...

 

[Joseph Garcia]

Yes. I checked those before I changed the compressor. The connectors above the frame were disconnected (accidentially). When they were disconnected I had a lot of messages on the dash (ABS, Tire Pressure, Traction Control....).
These little connectors seem to destroy everything

After that I only had the "Suspension"-Message - which is still there after installing the new compressor...

OK, good to know. Do you have access to a quality bi-directional scanner, so that we can see the actual trouble code(s) that are behind the dashboard warning? That would be the next step in getting closer to the root cause of the warning.

 

[tengelman]

I dont have. But I can check my local garage next monday.
Will keep you up to date then!

 

[tengelman]

Unfortunately the garge couldnt get no error codes. nothing.
Service suspension still appears.
The diagnostic tool also was not able to perform any kind of calibration of the ALC

Is there a way for me to reset without a special software tool?

 

[SpareParts]

Not that i know of. Takes a decent scanner to get suspension codes and reset it. The ALC reset might not be called ALC reset on scanners. On my scanner it is called something like Suspension reset, i don't remember for sure tho.
Did you install GM shocks or after market brand?
Does the compressor turn off or run a minute or so every so often. Could have a leak in the air lines. Once it does its little run after start up it should not run again if no load is added, if it does you have a leak.
Checked your fuses?
Module could be bad. Maybe the scanner used is inadequate.
First need to figure out why the scanner is not reading anything. Without that info, you're just throwing darts at a blank dart board.

 

[tengelman]

Sorry for delay! It took a while to find someone with a tech 2 Scanner thats decent enough for this.
Today was the day:
The error code says C0585-04 (left rear actuator circuit open).
So thats another wire-check-day for me next weekend...At least now I know where to look.

 

[Joseph Garcia]

According to Dr. Google, and I think that the troubleshooting steps sequence make sense.:

GM C0585-04 indicates a fault in the Left Rear Suspension Control Actuator Circuit, likely due to a wiring issue, damaged connector, or a faulty suspension damper itself. To troubleshoot, first inspect the left rear suspension wiring and connectors for damage or corrosion, then test the suspension damper's resistance. If the wiring is good, the problem is likely a faulty damper, which will need to be replaced.

1. Inspect the Wiring Harness and Connectors:

• Examine for Damage: Thoroughly inspect the wiring harness connected to the left rear suspension damper for any signs of rubbing, pinching, or corrosion.
  
  
• Check for Corrosion: Pay close attention to the electrical connectors for green corrosion, as this can indicate a poor connection.
  
  
• Verify Connections: Ensure that the connectors are fully seated and not loose or damaged.
  

2. Test the Suspension Damper (Shock Absorber):

• Measure Resistance:
  With the ignition OFF, disconnect the harness connector from the left rear suspension damper.
• Test the Damper:
  Using a multimeter, test the resistance of the damper between its control terminals.
• Compare to Specs:
  Compare the measured resistance to the specified range for your vehicle (refer to the vehicle's service manual, as this range can vary). If the resistance is not within the specified range, the damper is faulty and needs replacement.

3. Swap Connectors (If Necessary):

• Identify the Issue:
  If the wiring and damper resistance appear normal, you can perform a diagnostic test by swapping the left rear connector with the connector from the opposite side rear shock.
• Check for Fault:
  Clear the DTC and see if the code follows the connector to the other side. If the code now indicates the right rear shock, the connector itself is faulty and needs to be replaced.

4. Replace Faulty Components:

• Replace Damper: If testing confirms a faulty damper, replace it with a new one.
  
  
• Repair Wiring: If the wiring is damaged, repair or replace the damaged sections of the harness.
  

5. Clear and Re-Test:

• Clear the Code: After completing repairs, use a scan tool to clear the trouble codes.
  
  
• Verify the Repair: Drive the vehicle to see if the code returns, ensuring the system is functioning correctly and the suspension warning light is off.

 

[tengelman]

Hi!
Sorry the long time.
I was in hospital due to a intestinal obstruction...still not on top, but home again and I checked the wiring and the connectors. Everything looks fine. Also put some electric grease to every connector.
The wire that causes all the trouble should be the one in photo 1. That wire goes directly to a harness that goes to the front.
So I can´t swap the connectors to see if the error code goes to the other side.
Fram that harness there is a connector coming out that goes to the compressor (Photo 2, just routed it outside the frame just for the photo).

Next step yould be to measure the resistance of the damper. But I don´t know what would be the correct resistance...
Any Ideas?
(as this error message didn´t accur with the old rotten dampers and the broken compressor, I think its very unlikely that a bad wire inside the harness causes the trouble).

Regards
Dennis

 

[j91z28d1]

are the shocks oem?


since you still have the old shocks. check the resistance across the connector on the old ones? or maybe the one on the other side?

it seems like maybe you have a bad shock? electrically?

 

[j91z28d1]

oh the oem, I ask because I feel like I've seen someone post that the aftermarket ones might just be Airbag shocks with a resistor to trick the computer. not the actual mag ride fluid filled stuff. it something like they.

 

[Fless]

The second code -- C0050 04 -- is related to the right rear speed sensor. See the charm.li site below (but verify your vehicle info) for the diagnostic procedure; performing that may help you find the cause of the other DTC, in case they're somehow related.

C0050 — 2013 Cadillac Escalade RWD V8-6.0L Hybrid Service Manual | Operation CHARM

Detailed repair manual for the 2013 Cadillac Escalade RWD V8-6.0L Hybrid.

charm.li