Printer Friendly Forum Posts - starter start with dei 528t

hey guys, long story short, the IPDM [costs ~650$ to relace] on my M35 is messed up so the car wont start the way it supposed to. so what i want to do for the time being is to use a 528T to make my own start signal. i am trying to figure out the best way to wire it up. i need ~10 sec + signal to the starter module.

from my understanding:

red & yellow - batt +12v
black - chassis ground
BLACK/ w stripe - ign signal from push button
brown - starter

pretty much what i am trying to do is get the signal from when the push button is pressed to activate the 528T for ~10sec to send +12v to the starter.

TIA!

You drive a $45,000+ car and you're worried about a $650 part? :)

What year is your M35? What happened to the IPDM? Have you checked out Ebay or other places for used IPDMs? I would think you would be able to get a slightly used one for ~$250.

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Kevin Pierson

lol! i know right. its a 2006. i live in a golf course neighborhood where its all scenic and all. i mouse came up into the engine bay and chewed through a lot of the wires and loom going into the ipdm most likely shorting it out. when i took it out to clean up, resolder and all. the ipdm had a burnt smell. so with college pmt coming up, i figure this will be fine for a bit. at the moment i added a secondary bypass on/off toggle switch for the time being but its getting annoying. i haven't had time to run some diag tests to make sure all the wires are fixed so when i eventually get a new ipdm, it wont kill the new one as well. i looked around but never saw them for sale that cheap.

I would check in to a gray/red wire coming from the TCU to the IPDM. It should hit the IPDM on Pin 53 (16 pin connector) and should have 12vdc on it when the ignition is on and the car is in P or N. Without that 12vdc the starter solenoid won't get power.

The switch you added, are you controlling the actual amount of time the starter solenoid stays on or something else? I guess I"m confused because I don't know where the "10 second window" comes in to play.

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Kevin Pierson

yeah, that was one of the wires that was chewed up. i replaced the wire amongst many others, cleaned it up and soldeRED / heat shrinked it.

the m35 has push button start. what i have currently done is i removed the relay on the ipdm, from top left, the 4th one down. and i have made a connector that goes into the cabin wired to an on/off 30a toggle switch. when i push the start button and it goes to "on", i hit my switch and it jumps the starter. then i toggle the switch to off after 5-10 seconds. but i found out with the dei 528t, it can temporarily provide 12v for 5-90 sec.

also, would you mind pm'ing me ur #? i figure that would be easier to explain.

thanks again for all your help!

Have you checked the voltage on the gray/red wire? It is possible that you actually damaged the TCU, not the IPDM. If the IPDM was damaged I think you would be seeing many more problems then just the starter not starting.

If the gray/red wire isn't reading 12vdc you may be able to permanently tie that wire to a switched 12vdc signal - it would eliminate your "neutral safey switch" which prevents you from starting the car in gear, but for a short term quick fix I think it is a better choice then the 528t.

My concern with the 528t is that you will over or under crank the starter.

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Kevin Pierson

do, i didnt think of checking the voltage on that wire after the repair. is that line constant v or a temp signal?

the 528t as you know is adjustable in seconds. i figure id try and time how long i toggle the switch on to off and set it at that.

but i also like your idea but need a bit more help as to determine how i should hook it up.

when i did some continuity checks, it seemed that the starter relay fuse was not getting ground. i have some more notes when i get home ill post.

also, would it be possible for the pdu to be bad? on the relay, the coil gets energized from the signal from the tcm (53)(like u stated earlier) and the cpu of the ipdm. once that happens, the plunger closes on the pdu (4) and starter motor wire (3).

I wouldn't think the pdu would be bad, but anything is possible.

The only info I could find is that the signal from the TCU should be battery voltage when the shifter is in P or N. I would check this with a volt meter and if this isn't the case I would apply fused 12vdc to the wire and see if that "fixes" the problem.

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Kevin Pierson

understood. i have finals this week. i will try and check that this weekend or early next week and report back. again, thank you for all your help!

just tested the grey/red wire. when car is off, v = 0v. when the car is on, P & N is ~14v

Did you test that right at the IPDM?

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Kevin Pierson

yes, i tested the wire going into the connector. heres also an interesting observation, i extended all the wires so i would have more room to do some measurements and whatnot. the signal from the cpu is faulty so the relay doesnt energize. the signal from the PDU is fine. once i grounded the one to the cpu of the ipdm, terminal 3 (the middle one on the relay) got power. but heres the twist, the V coming from the TCM is fine @ 12v but when under load, it goes to ~0V.

Try this:

Disconnect the wire going to the TCM.

Measure for voltage and for ground on the IPDM side then measure for voltage and for ground on the TCM side. When working with the TCM side make sure the ignition is on and move the shift lever from P to D and observe any changes.

Next, try to start the car with your meter on the IPDM side. Again, while trying to start the car, measure for both voltage and ground on the IPDM side. It sounds, to me, like the TCM is supposed to be sending a ground to the IPDM. Another thing you can try is just straight grounding the IPDM side of the cut wire and seeing if the car will start.

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Kevin Pierson

from the fsm sc page:

STARTING SYSTEM PFP:00011
System Description NKS003NI
Power is supplied at all times
through 15A fuse (No. 78, located in the IPDM E/R)
to CPU of IPDM E/R,
through 15A fuse (No. 71, located in the IPDM E/R)
to CPU of IPDM E/R.
Ground is supplied
to IPDM E/R terminals 38 and 51
from grounds E22 and E43.
When the selector lever in the P or N position, power is supplied
from TCM, and through A/T assembly terminal 9
to IPDM E/R terminal 53.
And then provided that IPDM E/R receives a starter relay ON signal with CAN communication, starter relay is
energized.
With the ignition switch in the START position, power is supplied
through IPDM E/R terminal 3
to starter motor terminal 1.
The starter motor plunger closes and provides a closed circuit between the battery and starter motor. The
starter motor is

so my understanding would be if 12v is coming from the TCM, that would mean the IPDM cpu would be providing the ground?

also, from at-89:

9 GR/R Starter relay
Selector lever in “N”, “P” positions. Battery voltage
Selector lever in “R”, “D” positions. 0V

Yeah, that is what is sounds like - can you verify this voltage is present with a meter (and the wire unplugged from the IPDM)?

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Kevin Pierson

i guess i am a bit confused ... there is a wire (GR/R) coming from the AT TCM to the IPDM to E9(IPDM) so disconnect that connector (the E10-F1 junction) and measure the voltage & ground with the ign on switching gears?

so your saying i am thinking it backwards, the ipdm cpu should be giving 12v+ and the TCM give ground?

KPierson wrote:

Try this:

Disconnect the wire going to the TCM.

Measure for voltage and for ground on the IPDM side then measure for voltage and for ground on the TCM side. When working with the TCM side make sure the ignition is on and move the shift lever from P to D and observe any changes.

Next, try to start the car with your meter on the IPDM side. Again, while trying to start the car, measure for both voltage and ground on the IPDM side. It sounds, to me, like the TCM is supposed to be sending a ground to the IPDM. Another thing you can try is just straight grounding the IPDM side of the cut wire and seeing if the car will start.

what wire are you referring to when you say cut wire?

also, by looking at the fsm, would that help any for you to tell me what to do next?

sorry, i am i bit confused...

BrianR84 wrote:

what wire are you referring to when you say cut wire?

also, by looking at the fsm, would that help any for you to tell me what to do next?

sorry, i am i bit confused...

Cut the wire that goes from the tranny to the IPDM. You need to make sure that that signal is working properly. The service manual states it is a + wire, but I've seen mistakes in the FSM before.

I say to cut the wire because you will want to leave all the other wires hooked up while you are doing this test. You need to cut the wire to isolate the signals from the IPDM and the TCU. In a perfect world, with the wire cut, when you try to start the car there will be (+) voltage on one side of the cut wire and ground on the other side (thus energizing the internal relay).

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Kevin Pierson

i finally got a chance to do this. after i cut the wire, i measured ~12v from the IPDM side when the push button was pressed. also, i measured the other part of the cut wire and i got ~12v when testing for ground.