2020 AT4 - Cranking fast but not starting.

[aragrev7]

2020 AT4

46,000 km

Bumper-Bumper ended in April 2023. 
 

- Engine cranks very fast. 

- battery at 12.5V+. 

- Fuelled up. 
- many codes pop up after trying to crank, but the initial codes can be P062b, P0690, P16B3, P16BF. 
- occurs intermittently. I can be driving for days or weeks and then suddenly at my destination when I hop back in, no starting. 
- there is sometimes a bit of a lead up where the cranking takes slightly longer than usual. 
- when I disconnect the battery and ground the negative for 30 seconds, the truck will start again. 
- issue has occurred when mods were disconnected too. 

 

Electrical Mods:

- Putco Freedom Blade with plug harness adapter into tail lights. ACC voltage supplied from aero shutter fuse. 
- clearance LEDs tapped into marker light (left) fuse. 
- wireless trailer cam tapped into marker lights (right) fuse. 
 

Dealer 1:

- diagnose & taped up ECM harness (noticeable wear to wires): ~$500
 

Dealer 2:

- replaced power train harness: ~$500

- dealer 2 suggested replacing lower fuse box as next step. 
 

Has anybody had any similar issues? 
Any advice? 
Thanks!

[aragrev7]

Update 1:

- Speaking with tech, he suggests the truck is going into a “logic lock” due to an “unhappy module”. Disconnecting and grounding the electrical appears to be resetting the module.

- I will need to produce the fault and tow it in with the error active for him to try and determine which module is causing the issue. 

 

[newdude]

On 9/20/2023 at 1:00 AM, aragrev7 said:

2020 AT4

46,000 km

Bumper-Bumper ended in April 2023. 
 

- Engine cranks very fast. 

- battery at 12.5V+. 

- Fuelled up. 
- many codes pop up after trying to crank, but the initial codes can be P062b, P0690, P16B3, P16BF. 
- occurs intermittently. I can be driving for days or weeks and then suddenly at my destination when I hop back in, no starting. 
- there is sometimes a bit of a lead up where the cranking takes slightly longer than usual. 
- when I disconnect the battery and ground the negative for 30 seconds, the truck will start again. 
- issue has occurred when mods were disconnected too. 

 

Electrical Mods:

- Putco Freedom Blade with plug harness adapter into tail lights. ACC voltage supplied from aero shutter fuse. 
- clearance LEDs tapped into marker light (left) fuse. 
- wireless trailer cam tapped into marker lights (right) fuse. 
 

Dealer 1:

- diagnose & taped up ECM harness (noticeable wear to wires): ~$500
 

Dealer 2:

- replaced power train harness: ~$500

- dealer 2 suggested replacing lower fuse box as next step. 
 

Has anybody had any similar issues? 
Any advice? 
Thanks!

 

 

I'm thinking that its another harness chaffing issue they haven't found yet, but it could be a bad module, specifically the fuel pump power module seeing all those codes are fuel related.

 

I'd start by removing your aftermarket devices (unplugging) first as there are numerous issues that can occur with aftermarket devices installed on these 2019+up trucks.  For example, using the active aero shutter fuse for a power source isn't the best idea as the active shutters are a LIN BUS device and can set a CEL.  

[jbr1888]

Has the battery been tested? The voltage doesn't tell you how degraded the cranking capacity in Amps is. I recently replaced my battery on my 2019 because of similar crank/no start issue. Original batter was down to about 60% capacity. The electronics on these trucks are extremely sensitive and picky about the voltage they want to see. 

[aragrev7]

On 9/21/2023 at 1:34 PM, newdude said:

 

 

I'm thinking that its another harness chaffing issue they haven't found yet, but it could be a bad module, specifically the fuel pump power module seeing all those codes are fuel related.

 

I'd start by removing your aftermarket devices (unplugging) first as there are numerous issues that can occur with aftermarket devices installed on these 2019+up trucks.  For example, using the active aero shutter fuse for a power source isn't the best idea as the active shutters are a LIN BUS device and can set a CEL.  

good to know about the CEL on Aero circuit. (Curious how you knew that?). I called Putco and they are sending a relay to prevent 12V feedback into the circuit. 

 

At present, everything is disconnected and no logic lock issues. But I’m getting weird starts, such as hiccups or slightly longer turn overs. I even had a moment where I had just jumped in the truck and started it and the locks started rapidly locking and unlocking like a they were in full auto.  

 

On 9/25/2023 at 11:17 AM, jbr1888 said:

Has the battery been tested? The voltage doesn't tell you how degraded the cranking capacity in Amps is. I recently replaced my battery on my 2019 because of similar crank/no start issue. Original batter was down to about 60% capacity. The electronics on these trucks are extremely sensitive and picky about the voltage they want to see. 

Haven’t tested the battery load, however it is a new battery this year. Upgraded to an Odyssey 94R AGM for CCA and higher reserve capacity.  

[newdude]

1 hour ago, aragrev7 said:

good to know about the CEL on Aero circuit. (Curious how you knew that?). I called Putco and they are sending a relay to prevent 12V feedback into the circuit. 

 

 

 

The last gen trucks had the same deal.  CEL would be on, runs fine.  Shutter would fail and set a LIN BUS code which those LIN BUS codes would turn on the CEL.  U1510 is the most common on those trucks for example 2016-2019 K2XX trucks.