Hey guys my dad's 2013 Sentra is having issues with the radio. It has navigation and Bose system. I replaced the AV unit with an aftermarket android head unit and I still get the same issue. I already checked m the related fuses and they all check out good. Does anyone know where the accessory relay #2 is located? Looking at the diagram it looks like that relay is associated with the radio. Some times it turns on but then it turns off on it's own. I am an automotive technician bit i work on Lexus vehicles and their wiring diagrams/repair manuals are more in depth than the Nissan manuals i have found. The Nissan wiring diagram just says the relay is connector M65 but doesnt specify where that connector is. It just says the M in the connector means it's in the Main Harness. I'm thinking it's inside the dash near the BCM because when the radio does turn on you can hear a relay click. Not sure if it was coincidence or not but when i removed accessory relay #1 the radio would stay on.

For some reason the PDF '13+ Sentra FSM's are screwed up. The harness layouts are in the PG section for every other model. For the Sentra you need the EWD, which you can only access through ASIST. I can locate it for you, but not till Tuesday when I'm back at the shop.

VStar650CL wrote: ↑

Sun May 22, 2022 12:26 am

For some reason the PDF '13+ Sentra FSM's are screwed up. The harness layouts are in the PG section for every other model. For the Sentra you need the EWD, which you can only access through ASIST. I can locate it for you, but not till Tuesday when I'm back at the shop.

That works for me. I probably wouldn't be able to check it out untill Wednesday anyways since that's my days off. I even paid on the techinfo website to see if I could find something else. I was like how in the world do Nissan techs do electrical diagnosis with just what's in the repair manual lol. I appreciate it bro. And if you ever need Toyota or Lexus info I can look it up for you.

Is this a common issue with these cars? At first i thought it was the AV unit because when we get reboots on Lexus we usually replace the head unit and it fixes the isue if the software update didn't. But i was going to replace it anyways because the volume would go up and down on its own. I did replace acc relay #1 and even swapped it with the ignition relay next to it. Not sure if it was just coincidence but when i had both of those relays off and even just the acc relay #1 off the radio would turn on as soon as I turned the ignition switch and it would stay on. Once I put the relay back in it would start acting up again. I doubt the iPDM has any control over the radio right? And for the BCM it would affect other stuff right?

Yah, I checked Identifix myself and there was nothing in there. I think the only way to locate it will be the harness layouts in the EWD. Like I said, it weird that they aren't in the PDF's for Sentras, they're in there for every other model.

That kind of reboot behavior is usually software in the '14+ Navis because they used a brand new Bosch unit, but it's unusual in a '13. Since you replaced it with a 'Droid, that rules out AV software anyway. So I think you're on the right track checking out the relay. It's possible the driver transistor in the BCM is failing, it's a high-side (P-channel) driver chip instead of the usual ground-side N-channel. We have seen those occasionally crap out. If that's the case you should be able to do a work around by rewiring the Acc-2 Relay so its coil is driven by the output of the Acc-1 Relay.

VStar650CL wrote: ↑

Sun May 22, 2022 12:02 pm

Yah, I checked Identifix myself and there was nothing in there. I think the only way to locate it will be the harness layouts in the EWD. Like I said, it weird that they aren't in the PDF's for Sentras, they're in there for every other model.

That kind of reboot behavior is usually software in the '14+ Navis because they used a brand new Bosch unit, but it's unusual in a '13. Since you replaced it with a 'Droid, that rules out AV software anyway. So I think you're on the right track checking out the relay. It's possible the driver transistor in the BCM is failing, it's a high-side (P-channel) driver chip instead of the usual ground-side N-channel. We have seen those occasionally crap out. If that's the case you should be able to do a work around by rewiring the Acc-2 Relay so its coil is driven by the output of the Acc-1 Relay.

If the transistor is going bad would that throw a code for the BCM? I have a scan tool that can check codes for the BCM ECU. Not sure if it's related but there were codes for the a/c servos. My dad also said the radio was working the other day and as soon as he went to turn up the blower speed the radio tur Ed off. Cold have been just a coincidence though lol.

I was thinking of just adding a new wire to the radio and hook it up to acc 1 relay. Would the BCM need to be reprogrammed if i was to get one out of a salvage yard?

fcortes626 wrote: ↑

Sun May 22, 2022 9:30 pm

If the transistor is going bad would that throw a code for the BCM? I have a scan tool that can check codes for the BCM ECU. Not sure if it's related but there were codes for the a/c servos. My dad also said the radio was working the other day and as soon as he went to turn up the blower speed the radio tur Ed off. Cold have been just a coincidence though lol.

I was thinking of just adding a new wire to the radio and hook it up to acc 1 relay. Would the BCM need to be reprogrammed if i was to get one out of a salvage yard?

That sounds like maybe the A/C Auto Amp is the root of the problem. I haven't looked, but on most Nissans the A/C Amp is on the same Acc circuit with the radio. The transistor wouldn't produce a code even if it blew, none of the relay circuits have over-current detection except the Ignition-1 Relay. If it is the BCM causing the problem then yes, it will need configuration. If it's a used BCM you'll also need a new set of keys, the existing ones are paired to a BCM for life and only a brand new BCM will accept old keys.

Looks like it's up behind the fusebox.

VStar650CL wrote: ↑

Tue May 24, 2022 5:14 am

Looks like it's up behind the fusebox.
13 Sentra Main Harness.jpg

Thanks I'll take s look at it tomorrow.

VStar650CL wrote: ↑

Tue May 24, 2022 5:14 am

Looks like it's up behind the fusebox.
13 Sentra Main Harness.jpg

Bro thank you so much. Sure enough it is located right above the BCM. Tested it with my new lisle relay tester and it said it was bad. Replaced it with a new OEM relay and the radio turns on now.

You're most welcome, happy motoring!