A question worthy of fnkychkn

[His 'n' Hearse]

I don't often get the opportunity to use the cruise control on my '05 Mag SXT RWD, but I have and it was fine until it wasn't - like it didn't exist. 7,500 mi on the clock so it's off to the dealer for to exercise my warrantee. Here's what was typed on the service order when I picked up the car:

"checked and unable to retreive codes and according to star monitor all abs sensors and operating normal monitor input and output from switches and ok checked wires at steering module to pcm wt and lt to wt and lb and ok all wiring ok per star replaced steering control module and still inop, removed steering wheel and module to access and replace cruise switch per star still inop further investigator found pcm mileage at 12,000 miles tcm at 7500 reset both and retested ok"

The italics are mine and the actual copy was all caps but I didn't want to appear to be yelling.

So what the he!! does this mean, especially the italicized part? Anybody else had anything similar?

[MagnumFreak]

One of the many parameters these cars monitor and store in multiple places is the mileage. For whatever reason your pcm and tcm mileage readings where way offset. One of the more interesting parameters I have seen is the originally installed vin and current vin values. Great way to see if your module has been used on another car.


As far as why it would be way off, not sure on that one. Have you experienced any transmission issues?? I doubt that a tire size change would cause such a significant difference in mileage readings.

[His 'n' Hearse]

I ran 20" wheels for the first 2600 miles but the 255/40 Toyo Proxes S/T tires are within 0.1% of the stock 17inch-ers and the speedo is pretty much dead on with both so we can discount wheels/tires

The car was a 10/04 build and I bought it (supposedly) new from a dealer with like 24 miles on it on 7/31/05. No trans problems (although it shifts really mushy) and mileage has been ok.

Could this have been a used vehicle with a set back odometer?

[MagnumFreak]

I will hook up my starscan before I go home today and check to see if there is a difference between my pcm and tcm mileage. I doubt there was anything fishy going on at the dealer. May just have been a software problem.

[His 'n' Hearse]

IIRC, I don't think I had an opportunity to use the cruise control between when I got flashed for pulsating head/dash lights and I found it no workee. Maybe a relationship there?

.

[fnkychkn]

if voltage is detected on T751 circuit (fused ignition switch output [start])(PCM connector C1 pin 30) at anytime other than during crank, the PCM will disable the cruise. this voltage may be caused by an improperly installed aftermarket remote start or a defective diode in starter relay.

not sure as to why the mileage does not match.

[aries4life]

This is interesting.. quite the mystery. Even if you were running 10" tires (somehow) you'd still have the same mileage reading on both modules. Only way you could have a difference is if the TCM registered rotation and PCM used GPS lol

[eng1neer]

Didnt see TCM mileage on mine.. the PCM and FCM has it though... PCM was a bit off. Starscan says to verify within 100 miles of actual on odo. FCM and CCM were dead on.