code 42 est problem
07-09-2004, 10:53 AM
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code 42 est problem
Hey guys I dont post much here but when I have problems with my tbi thsi is where I come. Know this isnt in a f body car but ion my 87 3/4 ton suburban. it has a 5.7 tbi and I keep gettign a recurring code 42. this problem goes away as soon as the key is put to the off postiion and then is fine again until it happens again. the code is always has a hesitation prior to setting the check eng light and I beilve this is exactly what is happening
steps 1 thru 6 seem to be normal operating peramiters but step 7 is what has me puzzled where does the est feed back counter get its pulses from is it the knock sensor. the last statment ios what locks it in cause as soon as i **** of the ign switch it takes it out of bypass mode.
Any help would be great. just to let you know I have changed the ign. module 2 and the ecm has been replaced. I am thing the next thing is going to be either replace the bypass wire (I dont think this is the problem) or the knock sensor if it is what sends the pulse to the est counter. that sensor is what I really want to change.. thanks for the help. Oh by the way I know have 2 tbi chevys motors i am sure that one of them will get perfomance mods so I will be around to figure out how to squeak all the power out of them I can.
thanks again for the help tony
2.15.2 Code 42B
This portion of malfunction code 42 is intended to detail an open or grounded bypass line or a grounded EST line. This condition is detected under the following conditions:
1.Not in ALDL mode, Fuel backup mode or Spark backup mode.
2.Not in Factory test mode.
3.?QO msec time is enabled.
4.EST Major Loop Monitor is enabled.
5.Not in crank mode.
6.Engine speed greater than *KK42RM*.
7.No pulses received in the EST feedback counter.
8.This is the second consecutive occurrence of items 5, 6, and 7.
When the above conditions are met the EST logic will force the system into the bypass spark mode until the ignition switch is turned off.
Malfunction code 42 logic is executed once every 200 msec.
This portion of malfunction code 42 is intended to detail an open or grounded bypass line or a grounded EST line. This condition is detected under the following conditions:
1.Not in ALDL mode, Fuel backup mode or Spark backup mode.
2.Not in Factory test mode.
3.?QO msec time is enabled.
4.EST Major Loop Monitor is enabled.
5.Not in crank mode.
6.Engine speed greater than *KK42RM*.
7.No pulses received in the EST feedback counter.
8.This is the second consecutive occurrence of items 5, 6, and 7.
When the above conditions are met the EST logic will force the system into the bypass spark mode until the ignition switch is turned off.
Malfunction code 42 logic is executed once every 200 msec.
Any help would be great. just to let you know I have changed the ign. module 2 and the ecm has been replaced. I am thing the next thing is going to be either replace the bypass wire (I dont think this is the problem) or the knock sensor if it is what sends the pulse to the est counter. that sensor is what I really want to change.. thanks for the help. Oh by the way I know have 2 tbi chevys motors i am sure that one of them will get perfomance mods so I will be around to figure out how to squeak all the power out of them I can.
thanks again for the help tony
Last edited by 84cj7305; 07-13-2004 at 07:19 AM.
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