lmorris Posted June 30, 2011 Share Posted June 30, 2011 One more note to add to this, The engineers are now telling me that manual regen is not required when replacing the NOX sensor. I have a querry into hotline as to why and will update when they or if they respond. Here is my chat with hotline: Description of vehicle concern: MIL on, lacks power Diagnostics performed: koeo, checked oasis ssm 21894 perfromed roadtest and procedure, code still returns p164a, ppt rd DTC Codes: p164a Parts replaced: nox sensor Tech's question: Although not stated in pced for this code. Is manual regen still recommended to be performed after NOX replacement as well as ssm 21894 after replacement? Hotline response: Leon, The P164a is addressed in the latest PCM calibration update. Please perform TSB 11-04-21 to reprogram the PCM to the latest level. Once reprogrammed, perform the SSM drive cycle again. You do not need to perform a manual regen. The vehicles warranty repair history does not indicate the vehicle has been reflashed with the latest update. -------------------------------------------------------------------------------- Additional Diag/Comments Comment from: technician Comment Date: 6/30/2011 3:13:43 PM If I may be so bold. After replacing NOX sensors when all other attempts to repair P164A fail, why are we no longer performing the manual regen? Comment from: Hotline Comment Date: 6/30/2011 3:25:50 PM Leon, We were performing manual regen's to clean the soot off the original NOx sensor to see if this would resolve the concern. The soot build up on the sensor can cause the NOx sensor to react slower than it should and it can cause this issue. But since we are replacing the NOx sensors with updated parts, there is no reason for performing the manual regen for the p164a. If a regen is needed, then we can perform it. Please make sure we have installed NOx sensor part number BC3Z-9D378-G. Then perform the SSM and thoroughly retest. If the p164a returns, run through ppt KA 3 to make sure there are no leaks in the exhaust system. You do not need to perform the entire ppt, just KA 3. If there are no leaks, replace the NOx module, perform SSM 21894 and retest. Comment from: technician Comment Date: 6/30/2011 3:32:31 PM I was always under the assumption that manual regen was performed AFTER the new sensor was installed, not before. I have never been told to perform the regen to clean the sensor first, before replacing it,only after. Are the new sensors less prone to slowing down with soot build up? How do I know if regen is required? Comment from: Hotline Comment Date: 6/30/2011 3:48:05 PM Leon, That is correct. The updated sensors will be more responsive and less prone to issues with soot build up, etc. A regeneration can be performed if the PCM is currently requesting regeneration which would be indicated on the IC. Please proceed with the previously provided recommendation. If further assistance is needed, please contact the Technical Hotline by phone using the red contact ID listed on the hotline assistance request. The Technical Hotline can be reached at 1-800-826-4694. Am I missing something here? Were we not told to perform the regen after NOX replacement, not before? Quote Link to comment Share on other sites More sharing options...
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