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For that second bullet on post #14, I should have said "Same diagnostic result as prior testing when jumping the starter on the white wire". From post #8: "Jumping the white wire in the fuse panel creates a weak turnover for about half a second at very low rpm then stops for good. (Grind-halt)"
Jumping the white wire in the fuse panel creates a weak turnover for about half a second at very low rpm then stops for good.
A new starter, when given good 12V+ AND ground, should crank like there is no tomorrow. This is why I am leaning toward a power/ ground issue moreso than a control issue. A bad ground connection could hinder the starter and also cause the "lurching-like symptoms" your father experienced. As good as the electrics are on these cars, the ground connections leave much to be desired.
In addition to the continuity tests, I would just connect the NEGATIVE jumper cable directly from the NEGATIVE battery post to the engine itself (exhaust manifold usually works well) and see what happens.
Thankfully my father is retired and has another vehicle to use. I've been so frustrated with this vehicle I stopped working on it for a bit.
From above:
run a continuity test between the white wire at the IPDM/er to the starter. Disconnect from the IPDM/er and test from end to end. Should read zero (0) ohms;
it wouldn't hurt to check continuity on the main wire going from the battery directly to the starter motor itself;
CONFIRMED, from the + to the + post on the solenoid (under rubber flap) - 0 ohm
disconnect the white wire at the IPDM and, with a helper pushing the start button, read voltage at that pin on the IPDM/er. Should read 12V+;
no 12V - pushing the start button shuts off the car immediately
I replaced the IPDM with one on ebay, same serial#, and very similar described characteristics, no start, need to check 12V however.
check that the negative cable where it attaches to the frame is clean and solid. Alternatively, you can run a jumper cable directly from the negative battery post to the engine; and check the battery voltage at standing and also during cranking- this will help determine voltage drop
I jumped the ground, no start, same conditions (Neg from Bat neg to clean post on motor
I sanded the ground points I could find:
Two bolts at battery
Bolt at water neck at front of motor
2 at the left strut mount point
cleaned Battery + to Starter post
In addition to the continuity tests, I would just connect the NEGATIVE jumper cable directly from the NEGATIVE battery post to the engine itself (exhaust manifold usually works well) and see what happens.
Jumped the negative to ground the car with the jumper cable before cleaning the ground points, no start or crank.
I pulled the BCM out of it's housing. No indication of water infiltration, the board looks very clean with no sedimentation / oxidation between contacts.
I'm interpreting Pin 1 into the solenoid as the wire with the pigtail, and pin 2 in the schematic above as the terminal with a post and nut and rubber cover. Continuity aligns with this assumption.
It really feels like something before the IPDM is the issue as pressing the start button doesn't trigger 12+ at the IPDM pin 80. It seems unlikely that the starter relay in both of my IPDMs are failed but I will test those wtih a battery (believe it's the only relay at the top of the IPDM). My understanding is that the Starter Control Relay is not serviceable and is integrated in the IPDM. If this, then there are the systems before the starter relay that are problematic.
The ignition switch itself does not seem to be problematic - it turns the accessories on just fine.
I confirmed again the steering wheel turns fine (not locked out)
what do the square objects in the schematic represent? for example [8] between pin 80 and the solenoid. Does this represent a pigtail, or fuse?
I recently got a Foxwell 530 for a differetn vehicle (bi-directional scanner). I will load the Nissan software tonight and try to see if I can get any diagnostic info from the CANBUS/OBD.
How brave are you? I would try jumping the two starter posts like so:
In the old days we used a heavy-duty screwdriver. Essentially, this bypasses the solenoid (and the electronics above it) and checks to make sure the engine is free to spin.
On the IPDM, the STARTER CONTROL RELAY is the front one and user-serviceable:
It is the STARTER RELAY which is integrated into the IPDM/er and not user-serviceable. Why Nissan does it this way I have no idea...
If the engine is free to turn, and everything checks out- as it appears it does- then you have a issue between the BCM and IPDM. When you press the START button, the BCM verifies all of the security codes and, if happy, signals the IPDM/er to engage the starter. From the FSM:
12. BCM transmits the starter request signal via CAN communication to IPDM E/R and turns the starter relay in IPDM E/R ON if BCM judges that the engine start condition is satisfied.
13. IPDM E/R turns the starter control relay ON when receiving the starter request signal.
14. Battery power is supplied through the starter relay and the starter control relay to operate the starter motor to start the cranking.
Maybe others have some additional ideas because I am running out. I'm tagging @BULL here as he knows these systems a little better than I do.
Originally Posted by chitty
...what do the square objects in the schematic represent? for example [8] between pin 80 and the solenoid. Does this represent a pigtail, or fuse?
The square represents a joint connection (M/F connectors) and what pin within that joint this circuit travels. In this case, pin #8 of the E3 (male) and F1 (female) connectors.
Last edited by ILM-NC G37S; 08-16-2023 at 08:32 PM.
As always thanks again. It's not been fun having this vehicle down and all the neighbors walking by seeing no progress but the journey has been valuable and educational. You have been supremely helpful.
I probably don't want my arm up in there while trying to jump those two posts but I'll weld some mild steel rods together with a longer handle similar to the tool you describe.
I just listened a few times - No pump prime. The video above captures the sounds of the ACC on process pretty well.
Tried connecting the scanner just now. The power to the scanner is fine, but there is no connectivity (whether by OBD or Nissan / Infiniti dialogue).
Does the BCM run the communications for OBD / Diagnostics?
There is some light rust on the housing of the ECM behind the IPDM, but the ECM seems properly built to withstand the elements.
The dash menu works, the HVAC turns on and off, the center console LED interface works. Windows go up and down but act a little funky - when opening the driver door, the window will come down slightly but not go back up after closing the door.
The engine cranked when jumping pin 80 (albeit weakly), but nevertheless confirms non-seizure. There are neither relay nor solenoid clicks that I can hear when trying to start the car.
Based on those symptoms (no fuel prime, no OBD COM, etc.) something is not communicating with the rest of the car. Whether it is the BCM or the ECU hard to say, but I do think everything from the IPDM/er forward is fine. Typically, "wonky" windows point to the BCM.
You can try this (for "schlitz and giggles") ECU Reset aka Pedal Dance. This will reset the ECU and "might" re-establish OBD communication. Additionally, you can perform the IPDM/er Self Test. If the IPDM/er test proves good then we can rule out the CAN communication lines between the BCM & IPDM/er.
re: rust. Just make sure that any and all ground connections under that dash are clean and tight. Also, just as you checked the BCM for water/ corrosion, it would not hurt to do the same with the ECU (w/ battery disconnected, of course). Unplug and make sure the pins are clean/ dry/ etc.When you step on the brake pedal, do the brake lights in the rear turn ON?
- Did you check the fuses/ fusible links at the positive battery post and fuse box in front of battery?
- Any difference whether the fob is inserted in the slot?
- Does the steering wheel LOCK when everything is turned OFF?
I am sorry for throwing out a bunch of tests / questions, but I am afraid I am running out of ideas on this one...
Last edited by ILM-NC G37S; 08-17-2023 at 01:34 PM.
Wow those first two tests are really funny / complex! I will try to perform the IPDM test.
I think what I've been doing to the car is pretty much the full ecu reset (I pull the battery and keep it trickle charged), and the car has certainly sat for periods of days without power. I'll pull the ECU and take it apart to see what it looks like and perform the other tests.
Which is exactly what I recommended to do multiple posts above. The symptomatology has changed since as it appears the car is not fully turning ON. Thereby, the car is not initiating the engine start sequence. There is a control issue somewhere not a mechanical one.
Exact same issue but have the u1001 code confirming something isn't communicating within the systems. My passenger floorboard was wet after heavy rain and everything got wet. Unfortunately didn't realize it for a couple of weeks. Did anyone ever get the issue from the posts above figured out? I've went through all the steps detailed so far.
07-24-2023, 01:25 AM
