nine3shoof

I took my 2010 GSR in to get a P0017 checked out. I also got the system service required warning that in the big triangle, all pointing to a stretched chain. The current TSB, revised in January 2012, suggests that this could simply be a misdiagnosis caused by "an incorrect parameter in the judgement criteria".

The first step in the TSB is to update the ECM. Fair enough. The second step, added in the Jan 12 revision, is "to reset the Timing Chain Learned Value ".

The next step is to erase and read all fault codes, then perform a test drive to ensure codes do not return.

My concern here is the resetting bit. If the timing Chain Learned Value is reset to the current chain state, then haven't I just lost my baseline against which chain wear is measured? So if the chain was already at 0.5% stretch, even if this did incorrectly trigger a fault code, if that baseline is now set to 0.0, then by the time I add the 0.6% required to trigger another fault, the chain will be at 1.05 * 1.06 = 1.113 or 1.13% stretch. This is probably too late to avoid pistons hitting valves.

My dealer could not tell me whether or not this was an accurate interpretation, and suggested I call mitsubishi customer service. I did so, but was told that all technical information had to come from my dealer. I explained that the dealer did not know, and I was directed to a technical website with a $19.99 per day subscription. I couldn't get any detail on what this website provided, just that it was technical. I was also told their were no regional technical or customer service staff I could talk to.

Further, since the TSB did not require it, the original figure for stretch was not recorded.

I pulled the cam cover this evening, and followed the procedure to visually check stretch. It was close, very close in fact, but not beyond the limit.

My concern is that I now have no warning mechanism.

Can anyone throw any light on this? The cynic in me says it could be a very effective way of delaying a chain stretch warning beyond the warranty period... New software to remove the original diagnosis, followed by moving the baseline to delay a second fault trigger, but I don't actually believe that.

One more oddity... I was expecting to see an upper chain guard, but there isn't one! The bolt holes are there, but with no guard. Was this omitted on 2010 models?

Curioser and Curioser...

Peter Texas

Hahaha. Thats not surprising. I've had 2 stretched timing chains fixed by Younker Mitsubishi in Renton Washington State. When I installed the AMS CMC I noticed that the "boffins" at Younker Mitsubishi in Renton, WA "forgot" to re-install more than a few bolts. Genius crew.

Iowa999

iTrader: (1)

FYI, "boffin" is British slang for "scientist" or "academic" (in general).