Engine Failsafe Program 2002 540i/6 w/ INPA Datalog

[Iamthebull]

Update: I swapped in a brand new battery just to rule it out since I had one about to go into my dad's 528i.

I have INPA results of the car off, running, the voltage, and the ongoing error. Which, I know some are saying TB, but the error keeps pointing towards thermostat.

Additionally I cleared the error log and checked the errors again, and the same Thermostat related error shows up.

Thoughts?1e62c9d8f6e4ae1e2ce98c6434cab305-0.pngerror010923-622pm.pngerror010923-629pm-runningafterclear_1.pngerroranalog010923-runningnewbatt_1.jpg

[Chedley]

So, you mean INPA error code 140 = Map Cooling tstat activation. ?

Yes, that is a tstat gone bad and does not respond to DME commands. Specifically, it is a bad corroded electric connector/connections of the tstat. You will need to replace the thermostat.

[TiesTorN]

lol you guys are funny... how in the world a tstat error would prevent starting the engine?

tstat may be bad, but it's not the culprit here. it's just another problem for another time. most people (me included) doesn't even use that connector and always getting codes about it because of 88c tstat. it won't cause any issues.

[Chedley]

lol you guys are funny... how in the world a tstat error would prevent starting the engine?
.... .

It would not. The OP's problem is not starting the engine. It is the fail-safe message. Read Post #1.

[R Shaffner]

You still haven't replace the TB, right? In spite of the error? That's the next place to start after getting the battery straight. My N62 TB died intermittently too. Luckily I still had the one for my M62TU.

I doubt the thermostat would have any effect on failsafe errors.

[Iamthebull]

You still haven't replace the TB, right? In spite of the error? That's the next place to start after getting the battery straight. My N62 TB died intermittently too. Luckily I still had the one for my M62TU.

I doubt the thermostat would have any effect on failsafe errors.

Correct I have not yet. I'm going to the junk yard tomorrow to pick one up.

[Iamthebull]

Next update: Went to the salvage yard as they had just received an '04 X5 4.8is. Pulled the throttle body, and not thinking, it was the older/smaller throttle body that also goes on the 4.4 N62 motors.

I went ahead and ordered one off eBay. Should be here next week, will update once I receive and install.

[Iamthebull]

I have the car back up and running! I wanted to say thank you everyone for the help troubleshooting. It was indeed the throttle body. Got a used one swapped in and been running it all day, no issues.

Thank you again. I truly appreciate all of you.

[Iamthebull]

Well. Was out for a drive, and the error returned. Started right back up, it's idling high, right at 1000 RPM.
Car is able to drive fine otherwise, but I'm at a loss. Thoughts?

[R Shaffner]

Sorry. I feel your pain.
Rule #1 for intermittent problems is to check for something loose, like a wire or a bad connector.

[Chedley]

Well, that proves that it was NOT the throttle body after all.
My bet is on a loose wire or connector between the TB and the DME….When you replaced the TB you inadvertently fixed it for a while at least.

[R Shaffner]

Well, that proves that it was NOT the throttle body after all.
My bet is on a loose wire or connector between the TB and the DME….When you replaced the TB you inadvertently fixed it for a while at least.

I disagree. There are other possibilities. The previous error might have been the TB. There might also have been another error in the system, or there might be a new one now.

[Iamthebull]

I'll hook up the computer and see what I come up with tomorrow.

[TiesTorN]

actually there is no other possibility. those inpa codes were definitely tb related. it's probably something loose like chedley said.

one other thing you might check is the throttle position sensor. get in the digital values (or was it analog? dont remember) page under dme in inpa and check the throttle percentage as you press it gently. does it change accordingly?

[Iamthebull]

actually there is no other possibility. those inpa codes were definitely tb related. it's probably something loose like chedley said.

one other thing you might check is the throttle position sensor. get in the digital values (or was it analog? dont remember) page under dme in inpa and check the throttle percentage as you press it gently. does it change accordingly?

Previously when the car was running right, yes in INPA the digital values showed properly when hitting the throttle.

[kallekula]

So, the INPA error log in OP's first posting shows:
Supply voltage 10.93 volts for error 140 (thermostat)
Supply voltage 11.96 volts for error 130 (throttle DK)

1. That is a low or bad battery / alternator. Recharge the battery, and test the alternator. One should see a voltage of at least +12.4 volts with engine off, and +13.5 Volts with engine warm running.

2. Clean up the electric connections to the thermostat and the throttle. Reset the adaptations (engine off, key position 2, wait 35 seconds, remove key).
Erase all INPA errors, test drive , then scan again and report back.

About the battery voltage:
C02FCD3B-AECB-40B4-8096-596D47C4FC35.jpg

[Iamthebull]

Ha. Well. I believe I figured the darn thing out. So when I had upgraded to the N62 TB, it requires using an adapter as the pin out is different from the stock TB. Well, the guy that made it (forum member) might not have made the tightest of connections. After this came back, I got to thinking, what is the deal here? Why did it work so well after a day of driving with the new TB? Then I thought of that connector. I was stuck in a Walmart with the error again. Car was starting and dying. So I popped the hood, disconnected the TB, made sure it was GUTENTIGHT when plugging back in. Started right back up like a champ. Think I'm going to order a premade adapter from a shop, throw it on, and see how things go. Cross fingers.

Also no I didn't get around to connecting the laptop. It's been dang cold here

[Chedley]

Wait a minute ; don’t throw in a premade adapter yet.
You may want to prove your assumption by putting back the original M62 TB without any adapter, and see if it works. Remember to reset the adaptations after anytime you work on TB.

You could wait for spring warmer weather to do it. Meanwhile, Slap some electric black tape on the adapter to keep the N62 TB adapter guttentight, and keep the car running.

[Iamthebull]

Wait a minute ; don’t throw in a premade adapter yet.
You may want to prove your assumption by putting back the original M62 TB without any adapter, and see if it works. Remember to reset the adaptations after anytime you work on TB.

You could wait for spring warmer weather to do it. Meanwhile, Slap some electric black tape on the adapter to keep the N62 TB adapter guttentight, and keep the car running.

Not a bad idea. I'll play it by ear, see what happens. I just got my stock TB mailed back to me, so it's available if need be. Thanks for the insight Chedley

[Iamthebull]

Well. Most assuredly something with the connector. I had the issue arise again, limped it into Walmart, again. Picked up some electric contact cleaner, and before spraying the contacts with it, I decided to do a little test. With the car running I disconnected the cable to the throttle body. Immediately started idling up and down like in my initial post. Plug it back in, problem goes away. Hit the contacts with some cleaner, seems ok for the moment until I chase it down some more.

[Chedley]

Well, maybe the electric cleaner and tape are sufficient to fix --or mask ? -- the problem.
But longer term, you may want to replace the connector/adapter and rewire the whole thing between the TB and DME. You will need the pin-out diagrams of all those wires...

I am mulling the same thing with the MAF connector and wires.

[Iamthebull]

Well, maybe the electric cleaner and tape are sufficient to fix --or mask ? -- the problem.
But longer term, you may want to replace the connector/adapter and rewire the whole thing between the TB and DME. You will need the pin-out diagrams of all those wires...

I am mulling the same thing with the MAF connector and wires.

Yea I have the cabling and connectors to make my own adapter, I've just never done anything like that before. I remember a few years ago there was a thread on how to make it, but it seemed clear as mud.

I am going to get some dielectric grease though. It seems to be the connector going into the throttle body that is causing issues. Gonna pack it with the grease, just to add that extra layer of security.

[RsRichard]

Open the Elecricbox, disconnect the DME cables, check the middle big plug for the DME -> you will possibly find coolant which went all the way from Thermostat to DME. You are not the first one with exactly those symtoms and error on an M62 ;-)

[Iamthebull]

Open the Elecricbox, disconnect the DME cables, check the middle big plug for the DME -> you will possibly find coolant which went all the way from Thermostat to DME. You are not the first one with exactly those symtoms and error on an M62 ;-)

Already fixed the issue. In my case the connector to the throttle body was loose. Crazy, I know.