The basic question in this post is whether or not there is a problem.
On a trip this weekend, the instantaneous fuel economy on the Scan Gauge would jump to the 9999 display fairly frequently, holding that display for up to 30 seconds. If the 9999 occured during a coast down I would not be too concerned but in this case, the 9999 display was occuring during a cruise condition with the cruise on, and to a lesser extent with the cruise off. Several things were noted while trying to determine the cause of the display:
1) the display typically changed to the 9999 during acceleration for a hill, and the throttle position sensor (TPS) display went to 16. This also occured when the cruise was disengaged and the foot-feed was used to maintain speed.
2) when the 9999 was displayed, the car reverted to 'open loop'
3) no CELs or codes were thrown or stored in the SG
4) while the 9999 occured occasionally on the first day (around 0F with a tail wind) the problem was more frequent the 2nd day when traveling into a head wind and the car needed more throttle to maintain speed.
Is there any programming in the ECU that would explain this behavior?
Thanks!
On a trip this weekend, the instantaneous fuel economy on the Scan Gauge would jump to the 9999 display fairly frequently, holding that display for up to 30 seconds. If the 9999 occured during a coast down I would not be too concerned but in this case, the 9999 display was occuring during a cruise condition with the cruise on, and to a lesser extent with the cruise off. Several things were noted while trying to determine the cause of the display:
1) the display typically changed to the 9999 during acceleration for a hill, and the throttle position sensor (TPS) display went to 16. This also occured when the cruise was disengaged and the foot-feed was used to maintain speed.
2) when the 9999 was displayed, the car reverted to 'open loop'
3) no CELs or codes were thrown or stored in the SG
4) while the 9999 occured occasionally on the first day (around 0F with a tail wind) the problem was more frequent the 2nd day when traveling into a head wind and the car needed more throttle to maintain speed.
Is there any programming in the ECU that would explain this behavior?
Thanks!
