2010 220 Sundeck throwing engine faults

[farwellbooth]

Hello all,

I have a 5.7 L Merc with 419 hours in the Sundeck. Early this season I was occasionally getting a fault that would put the engine in guardian mode. The DTS display would say "Engine throttle level not operating properly". After shutting batteries off it would reset and run fine.

I'm not happy with the local SeaRay dealer in Seattle so I took it to the Cobalt dealer who works on Mercs but more so on the Cobalt Volvos. They hooked it up to the code reader, tightened some connections and it worked for a few weeks running 2x/week. System faulted again, took it back to Cobalt, tightened more connections, worked for a week...

Frustrated that Cobalt couldn't fix it I had the SeaRay dealer look at it. Being a 2010 they updated various firmwares and softwares etc. Boat ran great for a month. Boom, end of August system faulted again. Took it back to SeaRay and I'm getting a BUNCH of faults as follows:

Guardian_UXPowerLimit code 323
Engine MisFire code 396
Oil Pressure_Low code 12
Guardian_Active code 9
RxDoc1_SOH code 101
RxDoc110_SOH code 216
RxDoc7_SOH code 186
RxDoc9_SOH code 215
RxDoc3_SOH code 103
Dual_CAN_SOH_Faults code 150

The codes are time stamped and the last 6 happened at the same time. The SeaRay service people are unsure of what is going on. They have sent the codes to Mercury engineers for some help, so they say. The want to replace a sensor in the throttle level, a computer under the helm and the large fuse breaker on top of the engine. They admitted not knowing if this will fix the issue(s) or not. Any ideas on what is going on with the engine? I have had a trip planned to go to Canada in the boat next week, just got our NEXUS passes, have been trying hard to fix the boat and no one can figure it out. We are not taking the boat and going by ferry but I still need to find the gremlins... thanks

 

[Espos4]

I'm not a marine mechanic, but have many years experience as an auto mechanic.
How many batteries do you have? If 2, does this only happens when using a particular battery?
How old are they (it)?
The reason I ask is this, I have occasionally seen where an old battery causes weird things to happen. You appear to have several different problems, but may in fact only have one issue.

The CAN bus is basically a communication network where different modules can talk to one another. If one sensor has an internal defect, it causes chaos in the communication network and other components can generate error codes because of this.

One example, a customer brought in a Honda minivan with 2 problems, the ABS light was on and the power sliding doors didn't operate with the engine running, only with the key on and the engine off. A defective wheel speed sensor was replaced, and both issues were fixed. The wheel speed sensor somehow caused an error in another system totally unrelated to the ABS system.

My point of this long winded post is, don't go replacing everything at once. There may be only 1 culprit here causing the multiple codes.

If the battery(s) are old, replace them.
Clean all of the ground connections
disconnect, inspect, and clean the wire harness connectors.
If you still have issues, focus on the first symptom that came up, the "throttle level not operating properly"

By the way, GM 4.8 and 5.3 V-8's have a very common problem with faulty throttle position sensors. They too will cut engine power when a problem arises.

The throttle body on the GM automotive engine looks very similar to the one for a 350 MAG DTS.
There are 2 throttle position sensors inside the throttle body, and when they don't read the same throttle position, a fault code is set. I've replaced this on a customers car, and he said before bringing it for repair, shutting the engine off and restarting it would temporarily fix the issue.

Google P2135 and you will find some info and youtube videos explaining this.

Sorry for the long post, just trying to help.

 

[Espos4]

Keep us updated. Boat issues can take time to correct, but this would be a good future reference for anyone facing a similar issue.