Check engine light comes on when fan off switch is enabled

[Zach_M1078A1]

M1078a1
The check engine light comes on when I push the fan disable switch when I turn the switch off the check engine light goes back off

 

[GeneralDisorder]

You need to hook up CAT ET with a laptop and see what the code is when you hit the switch.

 

[Ronmar]

Yea, what general said. Way too many things can drive that light…

 

[Zach_M1078A1]

You need to hook up CAT ET with a laptop and see what the code is when you hit the switch.

I don’t have the software, cable, and my laptop is a mac. I’m hoping someone has had the same issue and knows what the problem is. Or has advice of possible cause

 

[GeneralDisorder]

I don’t have the software, cable, and my laptop is a mac. I’m hoping someone has had the same issue and knows what the problem is. Or has advice of possible cause

I've never heard of that. You might consult the wiring diagrams and see if you can discern any interaction.

If you own one of these and you desire/plan to troubleshoot and repair it yourself then you need to get the proper tools. And IMHO the disembodied hand of Steve Job's ghost can stay the F out of my wallet. Source: software engineer in a previous career path. A proper Windows laptop suitable for this purpose is about $250 or less.

 

[Ronmar]

Or in the interim, round up a cat tech, take the truck to them and have them scan it and analyze what the code is when the switch is engaged. The cost of one session however could equal the cost of the laptop and interface to start doing it yourself…

The ECU provides the power to control the fan solenoid and aux cooler relay. When it wants fan off, it powers the solenoid with 24v to provide the air that releases the fan clutch. When it wants fan on, it removes the 24 V to release the air and engage the fan. This power from the ECU passes thru the fan switch. When you flip the switch to disable the fan, it shifts the fan control power from the ECU to another 24V source which keeps the fan disabled for as long as the switch is in the fording/disable position.

could be the switch is mis-wired or has an issue, and when you set it to fan disable it is overloading the power output from the ECU? I have seen 2 different pinouts listed for the dash switches, so if someone at some point replaced a switch and used the wrong part, its config might not match the appropriate wires in the switch plug.

Do you have Air conditioning? I recall the air-con install taps something associated with that switch… I recall helping someone with a issue associated with that A/C wiring once upon a long time ago, but I do not recall the details…

 

[chucky]

Don use that switch unless your truck is in 3ft or more of water ! Which usally equates to never need to use that switch unless mother nature comes ah callin !

 

[Zach_M1078A1]

I've never heard of that. You might consult the wiring diagrams and see if you can discern any interaction.

If you own one of these and you desire/plan to troubleshoot and repair it yourself then you need to get the proper tools. And IMHO the disembodied hand of Steve Job's ghost can stay the F out of my wallet. Source: software engineer in a previous career path. A proper Windows laptop suitable for this purpose is about $250 or less.

Wow! I knew him as well when I worked for Lucent technologies in the bay area. I’m not a big fan either, but I would suggest you read about a man called Bill Gates and what he has been doing lately

 

[Zach_M1078A1]

Or in the interim, round up a cat tech, take the truck to them and have them scan it and analyze what the code is when the switch is engaged. The cost of one session however could equal the cost of the laptop and interface to start doing it yourself…

The ECU provides the power to control the fan solenoid and aux cooler relay. When it wants fan off, it powers the solenoid with 24v to provide the air that releases the fan clutch. When it wants fan on, it removes the 24 V to release the air and engage the fan. This power from the ECU passes thru the fan switch. When you flip the switch to disable the fan, it shifts the fan control power from the ECU to another 24V source which keeps the fan disabled for as long as the switch is in the fording/disable position.

could be the switch is mis-wired or has an issue, and when you set it to fan disable it is overloading the power output from the ECU? I have seen 2 different pinouts listed for the dash switches, so if someone at some point replaced a switch and used the wrong part, its config might not match the appropriate wires in the switch plug.

Do you have Air conditioning? I recall the air-con install taps something associated with that switch… I recall helping someone with a issue associated with that A/C wiring once upon a long time ago, but I do not recall the details…

Thank you this is great information

 

[Zach_M1078A1]

Or in the interim, round up a cat tech, take the truck to them and have them scan it and analyze what the code is when the switch is engaged. The cost of one session however could equal the cost of the laptop and interface to start doing it yourself…

The ECU provides the power to control the fan solenoid and aux cooler relay. When it wants fan off, it powers the solenoid with 24v to provide the air that releases the fan clutch. When it wants fan on, it removes the 24 V to release the air and engage the fan. This power from the ECU passes thru the fan switch. When you flip the switch to disable the fan, it shifts the fan control power from the ECU to another 24V source which keeps the fan disabled for as long as the switch is in the fording/disable position.

could be the switch is mis-wired or has an issue, and when you set it to fan disable it is overloading the power output from the ECU? I have seen 2 different pinouts listed for the dash switches, so if someone at some point replaced a switch and used the wrong part, its config might not match the appropriate wires in the switch plug.

Do you have Air conditioning? I recall the air-con install taps something associated with that switch… I recall helping someone with a issue associated with that A/C wiring once upon a long time ago, but I do not recall the details…

It does not have AC

 

[Zach_M1078A1]

Or in the interim, round up a cat tech, take the truck to them and have them scan it and analyze what the code is when the switch is engaged. The cost of one session however could equal the cost of the laptop and interface to start doing it yourself…

The ECU provides the power to control the fan solenoid and aux cooler relay. When it wants fan off, it powers the solenoid with 24v to provide the air that releases the fan clutch. When it wants fan on, it removes the 24 V to release the air and engage the fan. This power from the ECU passes thru the fan switch. When you flip the switch to disable the fan, it shifts the fan control power from the ECU to another 24V source which keeps the fan disabled for as long as the switch is in the fording/disable position.

could be the switch is mis-wired or has an issue, and when you set it to fan disable it is overloading the power output from the ECU? I have seen 2 different pinouts listed for the dash switches, so if someone at some point replaced a switch and used the wrong part, its config might not match the appropriate wires in the switch plug.

Do you have Air conditioning? I recall the air-con install taps something associated with that switch… I recall helping someone with a issue associated with that A/C wiring once upon a long time ago, but I do not recall the details…

It doesn’t have AC

 

[GeneralDisorder]

Wow! I knew him as well when I worked for Lucent technologies in the bay area. I’m not a big fan either, but I would suggest you read about a man called Bill Gates and what he has been doing lately

Very familiar with both. Lived that whole era in the industry.

Regardless - CAT ET doesn't run on anything but windows

 

[Zach_M1078A1]

Wow! I knew him as well when I worked for Lucent technologies in the bay area. I’m not a big fan either, but I would suggest you read about a man called Bill Gates and what he has been doing lately

That being said, I do plan on following your advice, but don’t think that windows is somehow less evil than Apple. It’s a choice between true evil and true evil plus plus

 

[Zach_M1078A1]

Very familiar with both. Lived that whole era in the industry.

Regardless - CAT ET doesn't run on anything but windows

Well put. I did too

 

[GeneralDisorder]

That being said, I do plan on following your advice, but don’t think that windows is somehow less evil than Apple. It’s a choice between true evil and true evil plus plus

Apple's walled garden software ecosystem and anti right-to-repair practices I find particularly insulting. At least on the PC side you can choose to run whatever software you want including other operating systems and no one is going to disable hardware features or prevent you from using non-OEM parts, etc. I haven't tried running CAT ET in a windows compatible environment but at least in theory it could probably be done.

Not that Caterpillar is much better with their practices - have to use cracked software to program their ECM's. Somewhat understandable for warranty concerns like rolling back mileage but things like locking down the C7 military serial numbered engines to only their original HP/TQ rating is pretty insulting. Oh well rather than make a few bucks on selling me the map they made nothing at all and lost all future programming revenue they might have got from me and all my friends by forcing me to crack their software.

 

[Zach_M1078A1]

Apple's walled garden software ecosystem and anti right-to-repair practices I find particularly insulting. At least on the PC side you can choose to run whatever software you want including other operating systems and no one is going to disable hardware features or prevent you from using non-OEM parts, etc. I haven't tried running CAT ET in a windows compatible environment but at least in theory it could probably be done.

Not that Caterpillar is much better with their practices - have to use cracked software to program their ECM's. Somewhat understandable for warranty concerns like rolling back mileage but things like locking down the C7 military serial numbered engines to only their original HP/TQ rating is pretty insulting. Oh well rather than make a few bucks on selling me the map they made nothing at all and lost all future programming revenue they might have got from me and all my friends by forcing me to crack their software.

I hear ya! And sorry about that. Hey, you should read about Bill Gates post. In hindsight it just sounds a little bitchy and snarky with a touch of Karen. My bad.

 

[Zach_M1078A1]

I hear ya! And sorry about that. Hey, you should read about Bill Gates post. In hindsight it just sounds a little bitchy and snarky with a touch of Karen. My bad.

Me - coffee = jerk