Help before I dive in...
 

Hey guys, I have a 2002 4.6is with 90k miles on it. Engine runs great but I do have the hard 2-1 downshift unless I drive it in sport. I noticed the other day it was whining (supercharger sound) at low speed acceleration. It doesn’t whine in neutral or park, so unfortunately its looking like I might have to do a TC replace/rebuild. However....I have noticed on a few occasions my battery light came on for a sec and then went away. Is it possible at all that my alternator could be going and the whining is coming from that? Hopefully it’s not just wishful thinking! I also need to change my fan belts, so I’m just wondering if I definitely have to change my TC? I have BC coilovers, axles, and rear subframe bushings going in next week (hoping it dissolves the 2-1 downshift issue), and if I have to do the TC I’ll do it while the car is up. Also, I have no trans shifting issues or codes that come up. Thoughts?

Low voltage can make all sorts of modules do crazy things, including the EGS. Did you check the battery voltage while the car is off and while running?

I would check vehicle voltage and if possible check for ATF fluid level.

You’re right I need to check the voltage, what numbers am I wanting to see while running and while off?

Yeah I’m thinking about doing a tranny service on it. Actually, I’m definitely gonna do it

A transmission service definitely helped with my 2-1 downshift although did not fully cure it but it is more than good enough to live with now. My battery light started to glow on idle when the alternator was on its way out, but would go out immediately if you upped the Revs anything from tick over. With the old alternator I regularly got the transmission failsafe warning as well as self level suspension inactive, but with a new alternator and decent battery everything is fine (for now ha!).

Checking voltage tomorrow at the parts store, I can’t find my tester :yikes: I drove it around the block today and noticed it whined in only first gear. After shifting into second, it went away. Either that or it got much quieter (hard to notice since with an upgraded exhaust it drowns a lot out). I’m hoping numbers come back wonky, leading me to change my alternator and fixing it. If not I’ll do a tranny service (which I’m doing anyways) to see if it fixes it. It only does whine though, when in sport mode it shifts and feel great. I’ll post voltage numbers tomorrow

You can monitor voltage real-time with the OBC hidden menu


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