2014 Nautique G21 PCM ZR450 - No Crank

[sebassim]

Hi everyone,

I am hoping someone with experience can help. I am based in Singapore, and unfortunately there are very few PCM technicians here.

The boat has developed a no-crank condition and I have spent several weeks troubleshooting it. I would really appreciate another set of experienced eyes

Boat Information

• 2014 Nautique G21
• PCM 6.0L (ZR450)
• Engine Serial Number: 740186

Original Symptoms

• Engine does not crank from the ignition key.
• LINC powers up normally.
• Fuel pump primes for approximately 2–3 seconds when the original boat key is turned to ON.
• Various relays/solenoids can be heard clicking during key ON.
• LINC does not display any engine data (oil pressure, engine temperature, battery voltage all read 0).
• DIACOM cannot establish communication with the ECM.

I have a video of the above in youtube

https://youtube.com/shorts/lJx9S_HqL...cWb_BoCHUgQxsX



Checks Already Performed

Starting System

• Batteries tested and confirmed good.
• Battery selector switch tested in Position 1, Position 2 and BOTH.
• Starter motor cranks normally when the starter solenoid is energized directly.
• Starter relay replaced with a new relay.
• Same symptoms remain.

Any advice from members familiar with PCM engines or would be greatly appreciated.


Sebastian

[bturner]

I really hate being a one trick pony here but there have been several guys having problems with the throttle base this season alone that have posted here. There are a couple threads on here with guys posting their replacement process and the symptoms they had with the base. Here's one of them for you to look at and see if it may fall into the symptoms you're seeing. You really need to verify which base was used on your boat but if it was one of the Livorsi models and you haven't replaced this part yet I would certainly be suspecting a base.....

https://www.planetnautique.com/vb5/f...nd-replacement

[jpwhit]

Sounds like a CAN BUS issue based on DIACOM not being able to talk to the ECU as well as the LINC screen not talking to the ECU and displaying engine stats. Unplug all non-essential devices to remove them from the CAN BUS. Start with the AIRMAR water temp and depth biducer since they have a history of causing CAN BUS issues when they fail. It’s a round black cylinder mounted through the hull typically right in front of the engine. Report back on if that fixes it. If not I can tell you what else to unplug.

[sebassim]

To add on, the boat was working fine without any incident during the last outing to sea 3 weeks ago.

We replaced the throttle body and throttle position sensor in 2022 with the following part
RA035044, VALVE, DBW THROTTLEBODY

does the throttle body breaks down again at the 4 years age?

nevertheless I shall do a check on the throttle body and neutral safety switch again this weekend.

[sebassim]

Sounds like a CAN BUS issue based on DIACOM not being able to talk to the ECU as well as the LINC screen not talking to the ECU and displaying engine stats. Unplug all non-essential devices to remove them from the CAN BUS. Start with the AIRMAR water temp and depth biducer since they have a history of causing CAN BUS issues when they fail. It’s a round black cylinder mounted through the hull typically right in front of the engine. Report back on if that fixes it. If not I can tell you what else to unplug.

thank you for the input. I will try that this weekend.

[DoubleUpDisaster]

bturner I think the 2015 was the first year with the throttle by wire setup. I’m pretty sure my 2014 G21 wasn’t.

[sebassim]

Sounds like a CAN BUS issue based on DIACOM not being able to talk to the ECU as well as the LINC screen not talking to the ECU and displaying engine stats. Unplug all non-essential devices to remove them from the CAN BUS. Start with the AIRMAR water temp and depth biducer since they have a history of causing CAN BUS issues when they fail. It’s a round black cylinder mounted through the hull typically right in front of the engine. Report back on if that fixes it. If not I can tell you what else to unplug.

I unplugged AIRMAR ,
rebooted LINC.
engine parameters still does not show.
Unable to crank.

I unplugged 3 ballast pumps,
blower, ballast sensor.
rebooted LINC. Same result as above

What else should I unplug ?

[jpwhit]

Here's a list of the other devices on the CanBus.

-GPS Puck
-One or more Power Distribution Modules (PDM) - unplug the green connector
-Keypad
-LINC screen itself
-Engine ECM - you can't really test this by unplugging, but the fact that fuel pump runs indicates it's not completely dead

I would actually go more by Diacom being able to connect to and talk to the engine ECM. Because beyond the GPS, PDMs you're starting to get into things that are essential. And if getting Diacom to work will let you see lots of other info. It's kinda too bad there isn't an easy way to isolate the engine from the rest of the boat. I think if you unplug the large round main engine harness connector, that the engine may lose it's power feed. But since the diagnostic connector is part of the engine's wiring harness, if you can get the engine isolated from the rest of the boat's CANBUS but still getting power, if Diacom can't talk to the engine ECM then that would tell you the problem is localized to the engine and it's harness.

Here's what the PDMs look like. It may be worth looking at the LINC PDM diagnostic screen to see if it can talk to them at all. That also may tell you how many PDMs the boat has. Here is what a PDM look like.

https://www.murcal.com/IX3212-PDM-12-VDC-58700012