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Discussion Starter #1
Hello everyone I've recently purchased this October, 1999 p38, and had a code for the sai not working properly (4112/4115 I believe) come up. I there is no power signal going to the pump at start up and the pump wont turn on. I have already changed the pump and the fusebox but still nothing. I also traced a brown/green wire back to the ecu and the was continuity, so I am pretty much stuck at this point. Any suggestions/help?
 

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1995-2002 Range Rover P38A
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assuming you replaced the relay with the fuse box I think you have to ground the wire at the ecu to verify pump operation. If all is well then scan the temp. sensor for the sai this is the sensor at the base of the radiator.If the temp. is high the sai will not operate. lastly and most unlikely it would be an ecu.These ecu's are almost bulletproof check everything else first then recheck before replacing the ecu.
 

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Discussion Starter #3
Well I took the ecu out and checked the fan to make sure it was working and it wasn't, in the rave manual its called the "e-box" fan and pulls air in from the cabin to cool down the radiator. If that has been out for sometime can it have caused the ecu to overheat and have inaccurate temp readings, that turn on the sai?
 

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I grounded the wire and the pump did indeed turn on. After some research there are two confirmed models with sai, the first turns the pump on according to the temp that the ecu has recorded. The second being the type that has a sensor on the radiator which determines when to turn on the pump. I took the ecu out and checked to see if the "e-box" fan was working, and it wasnt. Could this have caused the ecu to overheat and have inaccurate readings of temp, which would cause the fan to not turn on?
 

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1995-2002 Range Rover P38A
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very unlikely that the ecu overheated. the ebox fan is needed for instances of excessive heat. If the vehicle has lived in Cali its whole life it most likely in good shape. You need that fan in desert heat type temps.Do you have access to a scan tool or testbook? The temps. can be viewed also the ebox circuit is monitored by the ecu. The fault may not appear on all scan tools. I still have doubts about the ecu being at fault.
 
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