The check engine light on my S70 went on. The code was P0172, which was caused by a vacuum leak due to a hole in the little rubber elbow near the intake manifold--thanks for the clues, guys. I reset the OBD and now have gone through the driving sequence several times to try to get the monitors to indicate "done" but most of the sensors have not cleared yet. The ABS light is on, but I can't imagine that would prevent the emissions sensors from resetting. Does anyone have any clues? I still have several monitors that are not ready, so I suspect that I'm missing something fundamental. Thanks Bill
the s70 also suffers from ecu control module failures, especialy around the p and r reg range. some come up with the abs motor fault but ive never known one to fail. so its usualy the abs ecu which is mounted on the back of the abs modulator
This is from a Volvo Service bulletin. It's not an early April Fools joke. Good luck. Affected vehicles: Motronic 4.4, equipped with an automatic transmission Motronic 4.3, equipped with an automatic transmission OBD II Readiness Codes: Revised Reset Instructions Background The MY 1996, 1997 and 1998 Volvo 850/S70/V70/C70s require an extended driving period in order to reset readiness codes from INCOMPLETE to COMPLETE. When verifying an emission related repair, the TRIP identified in Section KKKK of the Engine Management System Service Manual TP 2308202 M 4.4 or Section EBU of the Engine Management System Service Manual TP 2301202 M 4.3 may not allow all of the diagnostic monitors to run. The following instructions, which supersede TRIP instructions contained in the above referenced service manual, will exercise all of the diagnostic monitors on these models. As long as no diagnostic trouble codes have been stored, the readiness codes will be set to COMPLETE upon completion of two consecutive trips driven according to the instructions. Introduction 1 This on-road driving sequence will allow all of the diagnostic functions an opportunity to run. After two correct, consecutive TRIPS, the readiness codes should be set to COMPLETE, provided no diagnostic trouble codes have been stored. General Instructions 2 Engine temperature at start must be below +50°C (122°F). Air conditioning (A/C) must be off during idle periods. A/C compressor activation during the Evap diagnostic may interrupt the Evap test. Select a suitable route where it is possible to safely stop at the side of the road. Obey all traffic regulations and posted speed limits. Trip Instructions 3 ^ Start engine ^ Move gear selector to Drive ^ Accelerate gently to 1500 - 2000 rpm ^ Drive for 6 minutes at 1500 - 2000 rpm ^ Safely stop the car and idle engine for 70 seconds with Drive engaged ^ Accelerate to 1600 - 2000 rpm ^ Drive for 6 minutes at 1600 - 2000 rpm ^ Stop the car and idle engine for 70 seconds with drive engaged ^ Accelerate to at least 45 mph, drive for 5 minutes at 1800 - 2200 rpm ^ Stop the car and idle engine for 60 seconds with Drive engaged ^ Accelerate to at least 45 mph, drive for 4 minutes at 1800 - 2200 rpm ^ Stop the car and idle engine for 60 seconds with Drive engaged ^ Drive the car to the location where it will be parked ^ Move gear selector to Park ^ Stop engine Finished -- Mike F. Thornhill (near Toronto), Ont. Replace tt with t (twice!) and remove parentheses to email me directly. (But I check the newsgroup more often than this email address.)
