If you're not getting power to the starter S terminal or Terminal #80 of the IPDM when trying to start the engine then it looks to be a problem on the control side of the starter circuit. I'd probably start by checking to see if the TCM is sending power to the starter and starter control relays. Does the dash display show that the transmission is in P? Check IPDM Terminal #72 (red/black wire) with a DVOM or computer safe test light. There should be battery voltage present at that terminal when the transmission is in P or N and no voltage in any other gear.

The factory service manual can be found for free here: https://www.nicoclub.com/nissan-service-manuals

 

I’m not sure about the indicator light but I did check terminal 72 and confirmed that it is getting power in park and neutral. I forgot to mention that she had a friend replace the starter button as well. I Need Coffee can you let me know how to check the TCM?

 

The BCM operates the control side of the starter relay solenoid so check IPDM Terminals #30 and #46 (both are brown wires). It should be the same as Terminal #72 (battery voltage in P and N and no voltage in any other gear).

Not sure what you want to check with the TCM. It's providing power when it's supposed to so it appears to be operating normally as far as the starter circuit is concerned.

 

Ok. I will check those terminals first thing in the morning. If either doesn’t have voltage what do you think the next step would be? I only ask because the car is not at my house so just wandering what the next steps might be. I will post back after I’ve checked them. Thank you so much!
Also what if they have voltage in any gear?

 

You would want to check what's going on with the transmission range switch circuit although that would be a secondary concern relative to the current no-start problem since power is being sent to the starter relays.

 

Also, even though the push button start switch was replaced, check that the IPDM can sense the signal when it's pushed. IPDM Terminal #28 (sky blue wire) should have battery voltage when the ignition switch is not pushed and 0 volts when the button is pushed.

 

BTW, do you know if the car has a steering lock mechanism? If unsure, check IPDM Terminal #11--if a pink wire is there then you have it, otherwise, you don't. If the car has a steering lock and it fails all kinds of weird no-start problems can happen.

 

Terminal 46 has no voltage, terminal 30 does. Terminal 28 has no voltage. It doesn’t have a steering lock. Even though the battery checked good I’m still going to go get a new one as we continue this diagnosis

 

Terminal 46 has no voltage, terminal 30 does. Terminal 28 has no voltage. It doesn’t have a steering lock. Even though the battery checked good I’m still going to go get a new one as we continue this diagnosis

 

Test for voltage at Terminal #46 again except this time disconnect connector E11 and test right at the pin on the IPDM rather than with the harness connected.

Do you have a scan tool that can read body (BCM) trouble codes (e.g. i.e. B2617 etc.)?

 

Unfortunately I don’t have a scan tool. Just checked pin 46 again unplugged and still no voltage. Also #28 the blue wire never has voltage. In fact when I check it with a test light it kicks out of accessory mode

 

Unfortunately I don’t have a scan tool. Just checked pin 46 again unplugged and still no voltage.

O.K. The reason I suggested testing again at the IPDM with harness connector unplugged is the voltages I'm citing are reference values in the service manual, but there's no context for those reference values in many cases. After looking at the wiring diagram again, Terminal #46 is after the solenoid in the relay so the BCM closing the control circuit would cause current to flow and voltage measured after the relay solenoid (which is a load) would be pulled down to zero (i.e. voltage drop). Thus, I wanted to make sure this wasn't the case by opening the circuit and testing at the IPDM unplugged in which case you should be able to measure the voltage potential supplied by the TCM on the other end of the control side of the relay, which should be battery voltage.

But, you're still getting nothing so I think the problem is the starter relay. Unfortunately, it's inside the IPDM soldered to the circuit board so there's no way to really test it and it's not considered serviceable by Nissan.

Also #28 the blue wire never has voltage. In fact when I check it with a test light it kicks out of accessory mode

As with the starter relay terminal, you can try testing right at the IPDM Terminal #28 with connector E10 unplugged though I'm not sure if voltage is sent out from this terminal based on other inputs. For example, when the TCM supplies power, that signal also goes to the IPDM's microcontroller as does battery voltage flowing through the load side of the starter relay and DTCs are thrown for the BCM if the starter relay is detected to be stuck open or closed, which is why I asked about the scan tool. I suspect that the voltage from #28 may be a confirmation signal sent from the IPDM to the BCM, but I can't be sure. Unfortunately, the start button function is not actually well described in the service manual. It's not even shown in the starter circuit diagram even though one needs to push it to start the engine. The only wiring diagram that shows the start button is for the BCM although there is no connector diagram as you typically find (weird), but if you look at the pin-out for the IPDM it shows Terminal #28 going to the start button, but the start button diagram only shows it connected to the BCM. Missing components and the relationship between systems not necessarily being well-described in the Nissan service manual in some cases can make things frustrating.

In any event, if it was my car I would check eBay for a used IPDM which you can find for as low as $20-30 and see if swapping it out fixes the no-start (...disconnect the battery and double-check that fuses are in the right place before plugging it in). There are two part numbers for the IPDM: 284B7-1AA0A and 284B7-1AA1A. I don't know what the difference is between the two, but go to nissanpartsdeal.com and enter your VIN and it should tell you which is the correct part (...you could also get this information from a dealership).

Please be sure to post back what you find, especially if the problem ends up being something else. But, I think the testing you've done points to a bad starter relay.

 

I will look for one on eBay and definitely follow up

 

I didn't follow all of coffee's debug stuff so I'm not certain if we know from the measurements made so far if the car is trying to crank or not? One quick thing came to mind that I didn't see mentioned was the brake interlock. There's a normally open and a normally closed switch that I believe have to correlate in order to enable cranking. There are some threads where this has been found to be the cause of a no-crank when one of them is bad. Relatively quick and easy to confirm that they're working compared to the more complicated stuff. And I think the car won't really tell you that one of the brake switches is bad. So all you get is a no crank (i think).

You may be able to tell if the car thinks you haven't satisfied the brake pedal interlock by cycling through the power modes (pressing the start button multiple times). If you press the button without your foot on the brake, it will cycle quickly from off - acc - on -off. If the car believes all the interlocks are satisfied and is actually trying to crank the starter, the cycle will be different. It will go from acc - crank (10s) - on - crank (10s) - on. For example when my starter was broken, the car was powering the S terminal but it didn't result in a crank or start so the car just holds the S terminal active for 10s and then gives up. So the timing of cycling through the power modes might look different if the car is trying to crank and can't like if the starter relay is bad versus if the car isn't even trying to crank because it thinks one of the several interlocks aren't satisfied. I guess I'm just trying to say how the car cycles through the power modes may tell you something (it may not but it's free and easy to do.....).

I may be way off here but at least it's easy to try. Just push the start button several times with your foot off the brake and watch how the lights on the button cycle. Then do the same thing with your foot on the brake and see if the cycle looks the same or different. If the car knows you have your foot on the brake and all interlocks are satisfied and it's actually trying to crank the starter (but failing to start), it should go back to ON mode after giving up (I think). If the brake interlock isn't satisfied, it will cycle back to off.

If you guys covered this already or somehow know that the car is or isn't trying to crank based on the measurements made so far, sorry for the long post. I just couldn't tell after one read through if we know the car is trying to crank for sure or is locked out from cranking.

Good luck and can't wait to hear what it is....

 

I didn’t know anything about the brake circuit 🤔

 

Here is a previous thread that was related to a won't start. I didn't read the whole thing to find out if it was indeed a brake switch problem but the brake switch debug video is linked in it. And that's worth a watch anyway.

https://www.nissanmurano.org/threads/murano-sl-2009-start-issue.227203/#post-774084

 

I didn’t know anything about the brake circuit 🤔

@jbarnett250 raises a good point--you can't start the engine if your foot isn't on the brake pedal and the BCM knows your foot is on the brake pedal. This is also a good example of what I was talking about in my previous post. Search the Starting System file of the service manual for "Stop Lamp Switch" and you'll get nothing even though the stop lamp switch is important in order to start the engine. The BCM confirms that the engine start condition is satisfied and then grounds the control side of the starter relay and sends the engine start signal to the IPDM over the CAN network. The "engine start condition" is the transmission in P/N, the brake pedal depressed, and the start button pushed--this information is in the section of the service manual that deals with the car's immobilizer and security system. You basically have to read like 4 different sections of the service manual to get a decent picture of what's going on when the engine is started.

What's going on with the starter relay though is independent of the stop lamp switch. You confirmed that battery power is flowing to one side of the starter relay solenoid via Terminal #72 of the IPDM, but no voltage is detected on the other side of that solenoid. There's something wrong with the relay.

However, the stop lamp switch may (or may not) be related to why you aren't seeing voltage on the push button switch Terminal #28 of the IPDM. Maybe also try the voltage tests with foot on the brake pedal and with harness connector disconnected and see if anything changes--post an update if you check this. In fact, you can also check if the BCM is grounding the starter relay from the connector where Terminal #46 is (...this would have been the next step if you did find battery voltage there).

Here is a previous thread that was related to a won't start. I didn't read the whole thing to find out if it was indeed a brake switch problem but the brake switch debug video is linked in it. And that's worth a watch anyway.

https://www.nissanmurano.org/threads/murano-sl-2009-start-issue.227203/#post-774084

I remember that thread. It was the starter. The dealership was also charging him for labor to replace the battery, which must be removed to replace the starter. I told him he should ask them to take that out and then they said they couldn't warranty the battery if they didn't charge for the labor, but came back and said they couldn't offer a 5 year warranty, but 1-year instead. That was stupid ridiculous.

 

@Scottrodds,

Just to get a verified reference point for voltage readings from an engine that does start, I did the tests on my car by back-probing the terminals with all connectors plugged in using a DVOM and this is what I got with just the ignition switch on and voltage at the battery of 12.4 volts when the tests were conducted:

Terminal #72 (TCM Power to Starter Relay - red/black wire): 11.9 volts
Terminal #30 (BCM P/N signal confirmation - brown wire) : 11.9 volts
Terminal #46 (Starter Relay Solenoid - brown wire) : 11.9 volts
Terminal #28 (Push-Button Start - sky blue wire) : 11.9 volts not pressed and 0.0 volts when pressed (...also read 11.9 volts with ignition off and button not pressed).

On a side note, I had initially grabbed my test light to conduct the tests and when I back-probed the TCM power feed (Terminal #72) the car pitched a fit! I heard a high-pitched tone (...I think it was the intelligent key warning buzzer) so I pulled out my probe and went inside the car to find the intelligent key light on the dashboard lit up and it wouldn't go out when cycling the ignition. The engine started normally though. I hooked up my scan tool and found three DTCs--one TCM (P0615: Starter Relay Circuit) and two BCM (B2603: Shift Position Status and B2604: PNP Switch). I cleared the codes and the key light went out. I was using my regular test light with an incandescent bulb instead of my other "computer safe" test light (...really just a logic probe) and what I think happened is the power feed from the TCM chose to go through my test light instead of to the starter relay (and BCM). The take home message (which I apparently forgot ) is that regular test lights have the potential to alter the function of a circuit so if one doesn't have a computer-safe test light then the tests should be done with a DVOM since there are multiple control modules monitoring these signals (...I edited my other post accordingly). This reminded me of something you said in an earlier post that the ignition was thrown out of accessory mode when you checked Terminal #28 with a test light--probably something similar happened.

 

I’m supposed to get the ipdm today. I will do these tests today. Thanks!

 

Ok. I changed the ipdm. Still won’t start. I rechecked all the terminals we talked about again but this time with a DVOM. All the terminals have voltage as normal except 80. Still nothing there. I checked on the brake switch. It is giving me the message to press brake, when I push the brake it doesn’t go off. I also cycled the push button like jbarnett250 said and it doesn’t seem to know I’m pushing the break. I checked both switches on the break pedal and if I did the ohm test right the switches seem to be working. I really think it has something to do with the brake. Is there any terminals I can check for the brakes? I’m lost

 

The brake lights come on, correct? When you push the brake pedal, battery voltage flows through the switch and then back to the fuse box under the dashboard where it branches out in at least three directions--to the tail lights, to the BCM (Terminal #118), and ABS Control Module (Terminal #16). If the brake lights come on then the switch works and voltage is flowing through it although I suppose there's a possibility of a wiring problem in the fuse box or further downstream preventing the voltage from reaching the BCM. Pushing the brake pedal doesn't make that notification on the dashboard go away--it turns off when the engine starts.

A few thoughts before moving on: Did you disconnect the battery at any point before installing the new IPDM? This should clear any BCM DTCs that might prevent the engine from cranking. Also, did you confirm the position of all the fuses in the replacement IPDM and that the fuses are still good (i.e. none are blown)? I would also suggest running the IPDM Auto Active Test to at least confirm the IPDM properly operates the components it directly controls that are easily visible.

If all that checks out, try measuring voltage at IPDM Terminal #46 (brown wire) while trying to start the engine (i.e. foot on brake and push-button start) to confirm whether or not the BCM grounds the control side of the starter relay--if it is then I would expect the voltage on Terminal #46 to drop to zero when the circuit is closed.

Sorry you're having to go through all this. This has turned out to be a tough one.

 

When I read through the starting system debug flowchart it sends you to the security control system chapter to debug the lack of S terminal voltage. Within the security control system chapter I get stuck on the power supply position table. The way I read the table below is that if you have your foot on the brake and the car knows you have your foot on the brake, it will NEVER go to the OFF/lock position if the engine doesn't start. It will always try to go from whatever position it's in to the start position. If either you don't have your foot on the brake or the car incorrectly thinks you don't have your foot on the brake, it will cycle as described below to the off/lock position. This is how you know if the car can detect your foot on the brake pedal. If you hold your foot on the brake and keep it there and push the button repeatedly and the car ever goes to the off state (no dash lights), the car doesn't know you have your foot on the brake.

I recall seeing this behavior now when I was debugging my bad starter. I was fooling around with the brake switches because I read it on the internet and when you disconnect one of them (or both I forget), the car will not shut off because it thinks you have your foot on the brake pedal and you're stuck in that one row of the table. Using that table below, it should be possible to determine if the car knows you have the brake interlock satisfied. If the brake interlock is satisfied, the car should repeatedly try to crank and fail and remain in one of the on states (acc or on). If it isn't satisfied, it will cycle around with multiple presses to the off position. How your debug goes depends on which of these paths you end up on. If the brake interlock is not satisfied then you have to figure out why. Sounds like you've measured the switches. There's also continuity to the BCM. That's also covered in the security control system chapter. If the brake interlock is satisfied and the car is trying to crank but the signal is not making its way to the S terminal, then you go down that path.

But I still think the first thing to do is spend 1 minute going through that table and seeing if the car cycles through the power positions with your foot on and off brake to be certain you're going down the right path. No parts, no disassembly, no measurements even. Just some basic observations. Good luck. Either path might be tough if the easy fixes are already eliminated (brake switch, starter relay, etc.).

 

The voltage on terminal 46 does drop to zero. I did the IPDM test and everything worked as it should. I also did the push button start according to the table above. Everything seemed right. When you push the brake and hit the button it does everything but start( it makes a very faint clicking noise briefly). And it stays in the “ON” position as long as you will let it until you hit the button again.

 

The voltage on terminal 46 does drop to zero. I did the IPDM test and everything worked as it should. I also did the push button start according to the table above. Everything seemed right. When you push the brake and hit the button it does everything but start( it makes a very faint clicking noise briefly). And it stays in the “ON” position as long as you will let it until you hit the button again.

I think this is actually good news. If the voltage on Terminal #46 is being pulled down to zero then the BCM is grounding the circuit and it would only do that if the necessary engine start conditions are met.

My next move would be to see if the starter control relay is getting voltage from the starter relay. There are two black relays visible on the top of the IPDM and the one on the driver side of the car is the starter control relay. See if you can remove the relay to do some more voltage testing. You'll need two thin flat-head screwdrivers on each side of the relay to apply upward pressure and a lot of patience since you don't want to damage the relay cover trying to get it out. It will come out though, just take your time and be careful.

Once the relay is out, use the picture below to test the relay sockets:

• Control-Side Power from TCM to IPDM Terminal #72: Battery voltage with ignition ON only.
• Power from Starter Relay: Battery voltage with cranking engine (ignition ON, foot on brake, push start button)
• Continuity Test Power to Terminal #80: With ignition OFF, unplug connector F12 and test continuity from relay socket to IPDM Terminal #80.

 

Oh man I thought the relays were soldered to the board and not accessible to measure. I thought it was odd that they'd be exposed like that but not be removable. But they're so recessed it looks like they might not be removable... not easily anyway. If we can measure the signals upstream of pin 80 all the way back to the battery, it's possible to confirm if the car is trying to crank or not and find out where the signal gets lost on the way to pin 80. Super unlucky that both IPDMs would have a problem though.

Based on the description of the clicking you heard, that sounds like the noises my car made when trying to crank when I had a bad starter. The car is probably trying to crank so you just have the measure the relay control pins and contact voltages that coffee pointed out and you should find it. You're almost there...

 

I’ve got voltage on power from tcu 72. No voltage on power from starter relay. I didn’t know where to hook the leads to do the continuity test?

 

I’ve got voltage on power from tcu 72. No voltage on power from starter relay.

Check for battery voltage at IPDM Terminal #36 (green wire) with ignition OFF. If there's no battery voltage at that terminal then check Fuse I (40 amps) in the fusible link block next to the IPDM and make sure it's good.

I didn’t know where to hook the leads to do the continuity test?

Just touch one lead to that pin in the relay socket and the other on Terminal #80. This is really just to confirm there's no break in the circuit between the starter control relay and Terminal #80--I doubt there is, but always good to check.

 

There is continuity on 80 and there is voltage on 36.

 

Just to confirm where we are right now:

• Terminal #46 (Starter Relay Solenoid - brown wire) has battery voltage with ignition on, but drops to zero voltage when trying to start the engine (foot on brake pedal w/ push start button).
• The starter control relay socket does NOT have battery voltage at the pin that runs to the starter relay (...and you made sure the probe is touching the metal pin in the relay socket)?

In a previous post after installing the replacement IPDM, you said the engine wouldn't start, but you heard a faint "clicking" noise. I suspected that was the starter relay. Temporarily reinsert the starter control relay (you can wrap a string around it to make it easier to remove again) and try the engine start again and listen to see if you can locate the clicking noise (preferably with a mechanic's stethoscope). The starter relay is literally in between the cooling fan #3 and starter control relays except it's under the plastic cover. I want to verify if that's what's clicking.

 

Ok so I double checked the 46 brown wire and it is NOT losing voltage when button is hit. The starter control relay socket does have 1.5 volts at pin. I can’t say for certain but there is definitely a click near that starter relay area

 

Damn. So, it looks like the BCM is not grounding the starter relay circuit after all. I'm not sure what that 1.5 volts on the starter control power socket is...that circuit does also connect to the IPDM, which I suspect is a sensing wire so maybe it's residual voltage from a transistor in there or something. There is no official testing procedure for the starter control relay outside of tests that can be run from the factory scan tool (CONSULT-III) since Nissan doesn't consider that relay serviceable even though you can physically remove it.

I think you're going to have to go right to the BCM and confirm that voltage from the starter relay is present and you can also test for voltage coming from the stop lamp switch while you're there. Unfortunately, you'll have to remove the instrument cluster to get to the BCM. You can find the procedures in the "Meter, Warning Lamp, and Indicator" file and "Instrument Panel" file (for the cluster lid) of the service manual: https://www.nicoclub.com/nissan-service-manuals

Voltages at the BCM should be as follows with ignition switch on unless otherwise noted:

Terminal #47 (Ignition Relay Control; Blue Wire): Battery voltage w/ ignition in OFF or ACC; 0.0 volts with ignition in ON.​

​

Terminal #52 (Starter Relay Control; Red Wire) : Battery voltage in P/N; 0.3 volts in any other gear; 0.0 volts with ignition OFF.​

​

Terminal #118 (Stop Lamp Switch; Blue Wire) : 0.0 volts with foot OFF brake pedal; Battery voltage with brake pedal DEPRESSED.​

​

Terminal #140 (Start Relay Power from TCM; Green Wire): Battery voltage in P/N; 0.0 volts in any other gear.​

For Terminal #52, also measure voltage while trying to start the engine (foot on brake pedal and push-button start) to see if voltage gets pulled down to 0 volts indicating the BCM is grounding the control side of the starter relay.

This is a time where it's really useful to have a scan tool that can read body codes. I'm pretty sure there's some fault codes logged in the BCM that might be helpful in troubleshooting.