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Matt
Matt, Mechanical Engineer
Category: Car
Satisfied Customers: 22258
Experience:  BEng hons Mech engineering, in auto industry 22 years
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RENAULT LAGUNA 1 1994 PETROL 1.8 RED "STOP" LITE ON DASH.

Customer Question

RENAULT LAGUNA 1 1994 PETROL 1.8 RED "STOP" LITE ON DASH. CAME HOME TUESDAY NITE NO PROBLEM, YESTERDAY THIS DAMNED RED LITE

TRIED:DISCONNECTING BATTERY WHOLE AFTERNOON,LOCKIN UNLOCKIN DOORS, PUSHED NOB ON END OF WIPER ARM, BUT NO FIGURES SHOW IN THE ODEMENTER SCREEN SO CAN'T SET IT TO 18,000 AS SUGGESTED?????

ERIC
Submitted: 4 years ago.
Category: Car
Expert:  Matt replied 4 years ago.
Hello Eric


does the car crank / turn over at all?

is the dash lighting up as normal ?

if it does start how does it drive with this light on?
Customer: replied 4 years ago.


YES IT STARTS FINE NORMALLY IT STARTS FIRST TOUCH DASH LITES ARE FINE HOWEVER NOW THAT YOU MENTION THAT LAST WEEK I BLEW A FUSE IN THE CIGAR LIGHTER WHICH TOOK OUT THE HEATER FAN AND THE DASH LITES I DIDNT REPLACE THE FUSE TILL THURSDAY BUT THE PROIBLEM IS THAT THERE IS NO INDICATION ON THE FUSEBOX LID WHICH DAMNED FUSE IS FOR THE LIGHTER SO I HAD TO CHECK THMEM; ALL ONE BY FLIPPIN ONE TILL FOUND IT


 


E

Expert:  Matt replied 4 years ago.
Hello

OK

this sounds like a fairly minor fault if its no effecting how the car drives

I'd check the level of the brake fluid 1st and if thats OK then consider having the car plugged into a diagnostic machine which will read off the fault code stored in the ECU (providing the light is still on at this point) and indicate which sensor has failed or whether the fault is more serious.

You can do a very rough and ready check yourself by unplugging sensors one at a time and seeing if any of them change the driving condition which would indicate the most recently unplugged sensor is the faulty one. This method is not foolproof though and reading a fault code off is the better method.

You can also try resetting the car by removing both battery leads and clamping them together for 10 mins as this will reset everything so if the light re-appears then the fault is still there.
Disconnect the battery cables and clamp them together for 10 mins. Remove both battery leads from the battery then use a nut and bolt or G-clamp to hold both battery lead terminals together.

This discharges any capacitors / memory within the ECU and around the car so ensures all memory settings are wiped clear - back to the factory default.

This will reset all the systems on the car and you may need the radio security code to get it going again, and ensure that the keys are in your hand when you re-connect the battery as the car may lock and turn on the alarm
Customer: replied 4 years ago.


OK,,,first point,,the car doesnt start at all as I already said, so how can I check the sensors under driving conditions if the car wont start?


 


Is their no other way to check the sensors?????


 


Second point, I am trying to avoid calling out a garage with their fancy diagnostic kit at 40 euros an hour, as I said at the beginning I am a pensioner and I can't afford that


 


Third point I tried your battery procedure, doesn't work in so much as the the red STOP lite is still ON and car won't start???


 


So what now?????? I NEED to be mobile monday ( tomorrow)


 


E

Expert:  Matt replied 4 years ago.
Hello

Sorry I misunderstood you as in your 2nd reply you said ' it starts fine'

Ok so if the car suddenly won't run and you have recently done some work inside the fusebox I'd get the voltmeter out and measure for 12V on the engine control relay in the box in the engine bay on the lhs at the front

do the same for the fuel pump relay in the same location

If the engine won't run but it does crank over then try measuring the resistance of the crank speed sensor at the gearbox end of the engine as it should be between 150 to 250 ohms