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cb750chris · 7th December 2018, 13:17

Just a quick question for Russ/Brian

Is it definitely the missing ambient air temperature signal thatinhibits the HRW?

Given the behavior in the car, (HRW disables a short time after you stall the engine) would the more likely data between ECU and HEVAC unit be the engine RPM? (so HRW does not operate if engine is turned stopped)? Obviously the same symptom in the even of a failed ECU, but seems to fit closer to observed behaviour with a working ECU.

7th December 2018, 13:17	#33
cb750chris Trader Rover 75 Tourer Join Date: Apr 2011 Location: Portsmouth Posts: 849 Thanks: 201 Thanked 292 Times in 200 Posts	Just a quick question for Russ/Brian Is it definitely the missing ambient air temperature signal thatinhibits the HRW? Given the behavior in the car, (HRW disables a short time after you stall the engine) would the more likely data between ECU and HEVAC unit be the engine RPM? (so HRW does not operate if engine is turned stopped)? Obviously the same symptom in the even of a failed ECU, but seems to fit closer to observed behaviour with a working ECU. __________________ Now offering T4 services in the Fareham area Replacement keys programmed / supplied / cut Diesel 135 upgrade available IPK virginisation and T4 matching available Sorry, due to a big change in home circumstances, I am unable to do any large jobs at present, but can still offer evening time diagnostics.