[JBee]

Bolax, just for giggles, pull the fan relay out and start the machine. Let it warm up to above the halfway point and plug it back in. Report back what happens.

Jeremy

 

[bollax]

Service manual says that the fan relay is activated by the ECM, with input from the coolant temperature sensor and/or the intake manifold pressure/temperature sensor.

You are 100% correct , that's how it works . Bollax did you try a new relay , as a bad one can't do weird things sometimes


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Swapped relay with Accy. relay same one and made no difference all is still the same.

 

[JBee]

Did you let it warm up to where the fan would normally kick on before plugging back in?

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[bollax]

Bolax, just for giggles, pull the fan relay out and start the machine. Let it warm up to above the halfway point and plug it back in. Report back what happens.

Jeremy

OK tried that, no bars show after 10 min idle but check engine light and message appeared.
replaced the relay & message went away ?

 

[JBee]

Fan come back on? Kinda sounds like a temp sensor

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[bollax]

Did you let it warm up to where the fan would normally kick on before plugging back in?

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Started w/o the relay installed and it ran for ten (10) minutes with no bars showing, just the check engine message. no bars at all ?

 

[bollax]

Bolax, just for giggles, pull the fan relay out and start the machine. Let it warm up to above the halfway point and plug it back in. Report back what happens.

Jeremy

Well second try is the Charm.
Let it cool back down and tried the routine again and it worked. put the relay back in at two bars and no fan.
looks like problem solved.
On to the next one.
Why did that work, what was / is the process ?
Is it a reset ?
Thanx again,
Ed

 

[JBee]

Bolax, just for giggles, pull the fan relay out and start the machine. Let it warm up to above the halfway point and plug it back in. Report back what happens.

Jeremy

Well second try is the Charm.
Let it cool back down and tried the routine again and it worked. put the relay back in at two bars and no fan.
looks like problem solved.
On to the next one.
Why did that work, what was / is the process ?
Is it a reset ?
Thanx again,
Ed

I Dont know why but, it did for me so I thought I would pass on the info...call it the jbee fan fix

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[bollax]

Bolax, just for giggles, pull the fan relay out and start the machine. Let it warm up to above the halfway point and plug it back in. Report back what happens.

Jeremy

Well second try is the Charm.
Let it cool back down and tried the routine again and it worked. put the relay back in at two bars and no fan.
looks like problem solved.
On to the next one.
Why did that work, what was / is the process ?
Is it a reset ?
Thanx again,
Ed

I Dont know why but, it did for me so I thought I would pass on the info...call it the jbee fan fix

Sent from my XT1080 using Tapatalk

Cool.
Thanx again

 

[bollax]

Well second try is the Charm.
Let it cool back down and tried the routine again and it worked. put the relay back in at two bars and no fan.
looks like problem solved.
On to the next one.
Why did that work, what was / is the process ?
Is it a reset ?
Thanx again,
Ed

I Dont know why but, it did for me so I thought I would pass on the info...call it the jbee fan fix

Sent from my XT1080 using Tapatalk

Cool.
Thanx again

Interesting side bar to Fan problem.
Jbee's idea worked, except after 88 miles at 3,000 ft ASL and 95deg. ambient temp running on pavement at 55 to 65 mph and parking the ride for six (6) hours on start up issue returned.
On the reverse ride home the fan came on at cold start up, on the ride home the temp bars reached six (6) for a while again at 3,000 ft & 55 to 65 mph on blacktop with same temp. Slowed to about 45 for a couple miles bars went to four (4) and then to three (3) had to stop for a Military check point for about five (5) minutes and all was back to normal three (3) bars and no fan, turned on the DZ fan control and rode the last 50 miles at 55 to 60 at two / three bars. The altitude does contribute to the temp as well as fuel economy.
I guess gremlins come & gremlins go.
Still would like to know what happened.
FYI We were running as chase vehicle for the Baja 500 race so that's the pavement, speed & altitude answer.

 

[bollax]

I Dont know why but, it did for me so I thought I would pass on the info...call it the jbee fan fix

Sent from my XT1080 using Tapatalk

Cool.
Thanx again

Interesting side bar to Fan problem.
Jbee's idea worked, except after 88 miles at 3,000 ft ASL and 95deg. ambient temp running on pavement at 55 to 65 mph and parking the ride for six (6) hours on start up issue returned.
On the reverse ride home the fan came on at cold start up, on the ride home the temp bars reached six (6) for a while again at 3,000 ft & 55 to 65 mph on blacktop with same temp. Slowed to about 45 for a couple miles bars went to four (4) and then to three (3) had to stop for a Military check point for about five (5) minutes and all was back to normal three (3) bars and no fan, turned on the DZ fan control and rode the last 50 miles at 55 to 60 at two / three bars. The altitude does contribute to the temp as well as fuel economy.
I guess gremlins come & gremlins go.
Still would like to know what happened.
FYI We were running as chase vehicle for the Baja 500 race so that's the pavement, speed & altitude answer.

Guess I g\have to bump it to keep it alive?

 

[209aspen]

It happened to my 2011 commander right after I washed it. I pulled fuses and relays and checked the sensor so I ended up taking it to a dealer they had it for almost two weeks and basically they pulled fuses and ended up flashing the ECM and the fan came off. Haven't had any problems since not sure if that helps but that was my experience.

 

[slowindown]

Well I just had this happen to me: start commander from a cold start and the fan would run continuously. But it wouldn’t run with just the key on like it normally would if you turned it off when hot where it will normally run until cool or the computer powers down. Of course I could never get it hot.

So I swapped the acc relay with the fan relay. No change. Then I found this thread and did what JBEE said - pull the relay and run the machine until the temp bars are where the fan would normally kick on and then plug the relay back in. This seems to have fixed it.

Ed, you said it recurred after about 90 miles. Did you, or anyone ever figure out the source of the problem?

 

[cannedham]

I wonder about the MAPTS connection or cleaning. It doesn't seem to be stuck relay contacts or follow input from the coolant temp sensor, unless that circuit is reading open at start-up.

 

[slowindown]

I don't know. The fact that it didn't run with just the key on was odd - only after the engine was running. Jbee's procedure performed some sort of reset. I used it some this afternoon and it is back to normal after that "reset".

Maybe Ed will pop back in. I know he's still on the forum.

 

[slowindown]

What is a MAPTS connection cannedham?

I had to reset it again this morning after about 40 miles of use over the last few days. I texted Ed but he didn't remember for sure what the underlying issue was. He thought maybe he replaced the relay. Regardless, he hasn't had any more trouble since 2014 with it.

I did find and order a couple of new relays on ebay but I don't think that is the underlying problem since when checking things out and before I did the reset procedure, I switched the fan and acc relays.

Any ideas?

 

[cannedham]

It's the MAP sensor. It measures air intake pressure and temperature. That's why I posted that chart above for you (post# 34). We discuss a lot here about cleaning it, and I wondered if even the connection for it might cause a problem. I'm just trying to find something relating to temperature input to cause your problem. Seems like I read in the manual that the ECM takes a reading from the sensor with key on, then another reading when the engine is running. But it doesn't specify whether it's taking just a pressure reading or temp and pressure. Does he maybe remember if he cleaned or replaced the MAPT?