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Engine shutting off?

4K views 18 replies 6 participants last post by  MoistCabbage 
#1 ·
So I was driving to work today, and suddenly the engine cuts out and that light with an exclamation point inside a gear comes on. What the heck could that be? It doesn't wanna crank when I try to start it, but a few hours later it starts up just fine only to shut off again 15 minutes down the road. I'm typing this on the side of the road as we speak. Please help!
 
#3 ·
Probably it's the CPS acting up. I had the same problem last year, was at the stop light and the car just turned off and it would not start and didn't get any warning lights. I waited about 30 minutes then tried again and it started and shut down after 5 mins then waited again for another 30 minutes and fired back up made it my house. I replaced the CPS and no issues now.


Thanks.
 
#8 ·
The problem isn't with the sensor itself but its wire. Heat from the exhaust manifold cooks the conductor and it cracks. After a cooling period the crack closes and the engine will fire then the cycle repeats. When you replace the CPS add more heat insulation. A longer length of shielding, a loose sheath of aluminum foil works well.
 
#17 ·
When a problem is occurring, a code is set as "current", as in happening now. If the problem goes away, the code is stored as "history", for a number of ignition cycles.

Example: When my MAP sensor failed, the CES was never triggered, and there was never a current code , only a history code. I could clear them, start the car, and the MAP code would immediately be in history. This points to an intermittent fault, that doesn't last long enough to meet the criteria of triggering the CEL.
 
#18 · (Edited)
I don't get the history codes with my scanner in the Catera, I wonder if you need a special scanner like they would have at the dealer.

With my Catera, I get "current codes" and "pending codes". The pending codes are codes that the computer is tracking, for example if setting a code requires that the test fail 3 times in so many warm up cycles, it may have two of those failures.

Among other things, one of the functions of the history codes is to keep you from faking the state emissions test by resetting the codes before you go for the test. This history codes remain. I can't read them with my scanner, not sure if it is a function of not having a sophisticated enough scanner, or maybe it is the particular protocol used by the Catera.
 
#19 ·
History codes do not remain when the codes are cleared. In order to pass inspection, OBD must be "ready", meaning all monitored systems/components have had a chance to operate, and did so as expected. If the codes are cleared, the system will not be "ready" until you have completed one full "driving cycle" (google it).
 
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