MIL warning light.
Discussion
To carry on the theme of 'if anything can go wrong it will go wrong this weekend' I have another problem !!
10 miles from The Growl this afternoon I notice my MIL light come on. Managed to get hold of Mr Whalley from Torque V8 (thanks for the help, much appreciated, and sorry about the random phone call but you were the only person I had a number for !!) who adised to reset the ecu.
This I did, sure enough the warning light went out and the car continued on its way. Half an hour later it happened again, so I went through the same process and the light went out again. On arriving home exactly the same happened. It all seem OK now and the light is staying out. The car was and is still driving beautifully and the oil pressure is fine.
Whats my next step ? Wait until I get the car on the rollers to be set up with Mark Adams in a few weeks (hopefully) or get it in somewhere tomorrow ? What are the possible causes of the light coming on and am I going to kill the car if I drive it any further ?!!
As most of you know, the car has just had a few improvements made (plenum, AFM, pre cats removed, carbon trumpets and Tornado chip) and it ran well on the rollers at the Growl hitting 290 and a bit BHP after the fuel pressure regulator was turned down from 3 bar to 2.5 bar as it was over fuelling. The mods have transformed the way the car drives and accelerates etc but my MIL light is coming on. please help !!
10 miles from The Growl this afternoon I notice my MIL light come on. Managed to get hold of Mr Whalley from Torque V8 (thanks for the help, much appreciated, and sorry about the random phone call but you were the only person I had a number for !!) who adised to reset the ecu.
This I did, sure enough the warning light went out and the car continued on its way. Half an hour later it happened again, so I went through the same process and the light went out again. On arriving home exactly the same happened. It all seem OK now and the light is staying out. The car was and is still driving beautifully and the oil pressure is fine.
Whats my next step ? Wait until I get the car on the rollers to be set up with Mark Adams in a few weeks (hopefully) or get it in somewhere tomorrow ? What are the possible causes of the light coming on and am I going to kill the car if I drive it any further ?!!
As most of you know, the car has just had a few improvements made (plenum, AFM, pre cats removed, carbon trumpets and Tornado chip) and it ran well on the rollers at the Growl hitting 290 and a bit BHP after the fuel pressure regulator was turned down from 3 bar to 2.5 bar as it was over fuelling. The mods have transformed the way the car drives and accelerates etc but my MIL light is coming on. please help !!
Is it just driven by the FI system, thought it was driven from the ECU and can be triggered by a number of sensor outputs going out of spec (pre determined safe operating ranges/specs etc) Does yours have a fuel pressure sensor ? Some have the rail with the fitting, but not all are fitted with em. Mine wasn't for example, so I'm less inclined to believe yours is and it may be the change from the Growl as it was fine before?
As highlighted above, a fault code reader is the only way to tell the exact reason. Resetting the ECU is only a temp fix.
As highlighted above, a fault code reader is the only way to tell the exact reason. Resetting the ECU is only a temp fix.
The ECU warning light to come on if the correct air fuel ratio cannot be maintained, or failure in one of the sensors and the ECU will drop into the "get you home " mode. This causes the ECU to default to a "fixed fueling" map, that can run without sensor inputs. This will limit the cars performance and tends to run a bit rich, until the fault can be cleared.
To get a full diagnostic a fuel injection fault display has to be plugged into a socket in the wiring loom above the ECU that provides two-digit diagnostic codes.
Here are the possible fault codes:
02 ECU Supply has been disconnected
Normal code to get after ECU has been reset. May indicate supply problems if ECU has not been reset recently. Code will be cleared if the ignition is turned on for 30 seconds or so
03 Data corrupted. Corrupted data in ECU. Reset ECU and test drive again.
12 Airflow meter out of range Possible faulty airflow meter or connection/wiring fault.
14 Coolant thermistor out of range. Possible faulty coolant thermistor or connection/wiring fault.
15 Fuel thermistor out of range. Possible faulty coolant thermistor or connection/wiring fault.
17 Throttle pot out of range. Possible faulty throttle potentiometer / incorrect setting or connection/wiring fault.
18 Throttle pot output too high with low airflow. Major air leak between airflow meter and intake plenum. Possible faulty airflow meter or throttle potentiometer or wiring/connections to either.
19 Throttle sensor output too low with high airflow. Possible faulty airflow meter or throttle potentiometer or wiring/connections to either.
21 Tune resistor out of range Tune resistor has become disconnected / damaged.
23 Low fuel pressure. Possible faulty fuel pump/ blocked filter or faulty fuel pressure regulator. VALID FOR CAT CARS ONLY.
25 Misfire at full load. A misfire has been detected while engine under heavy throttle and during high airflow meter readings. Check coil/plugs/leads/ distributor and ignition module. Code means that lambda sensors have detected a rich condition under load. Also see codes 40 and 50. VALID FOR CAT CARS ONLY.
28 Air leak. Air leak around intake plenum. Check all hoses/ injector seals etc.
29 Checksum error. ECU fault. Try resetting ECU and test driving again. If fault code returns ECU may be faulty. NOTE – any other codes generated should be ignored.
34 Fuelling fault in nearside injector bank. For cylinders 1-3-5-7 Possible injector, lambda sensor fault or wiring / connection fault to either. Blocked injector(s) or air leak at injector /inlet manifold. VALID FOR CAT CARS ONLY.
36 Fuelling fault in offside injector bank. For cylinders 2-4-6-8. Possible injector, lambda sensor fault or wiring / connection fault to either. Blocked injector(s) or air leak at injector /inlet manifold. VALID FOR CAT CARS ONLY.
40 Misfire on nearside bank. Misfire on 1-3-5-7 cylinders only. Nearside lambda sensor has detected a fault (or fault in lambda sensor circuit). VALID FOR CAT CARS ONLY
44 Offside lambda sensor out of range. Possible faulty lambda sensor or wiring/connection fault. See section 5 below for check. If in conjunction with code 45 then suspect lambda heater circuit. VALID FOR CAT CARS ONLY
45 Nearside lambda sensor out of range. Possible faulty lambda sensor or wiring/connection fault. See section 5 below for check. If in conjunction with code 44 then suspect lambda heater circuit. VALID FOR CAT CARS ONLY
48 Stepper motor fully open below 500rpm or fully closed above 750rpm. Possible faulty stepper motor or wiring connections. Stepper motor needs cleaning / is jammed. Incorrectly set idle adjustment screw. Incorrectly set throttle butterfly. Misfire or rough running because of other faults.
50 Misfire on offside bank Misfire on 2-4-6-8 cylinders only. Offside lambda sensor has detected a fault (or fault in lambda sensor circuit). VALID FOR CAT CARS ONLY
58 ECU cannot distinguish between codes 23 and 28. Fault maybe either due to code 23 or 28.
59 Same as 58 or fuel thermistor out of range. Documentation seems to vary here. Code either means same as 58, or faulty fuel thermistor or wiring / connector fault.
68 Road speed sensor too low at medium rpm and high airflow. Possible speed sensor or wiring/ connection fault.
88 Power-up check / purge valve fault. Sometimes shown on power up (CAT and NON-CAT CARS ) or could also indicate purge valve fault with carbon canister system. (CAT CARS ONLY)
To get a full diagnostic a fuel injection fault display has to be plugged into a socket in the wiring loom above the ECU that provides two-digit diagnostic codes.
Here are the possible fault codes:
02 ECU Supply has been disconnected
Normal code to get after ECU has been reset. May indicate supply problems if ECU has not been reset recently. Code will be cleared if the ignition is turned on for 30 seconds or so
03 Data corrupted. Corrupted data in ECU. Reset ECU and test drive again.
12 Airflow meter out of range Possible faulty airflow meter or connection/wiring fault.
14 Coolant thermistor out of range. Possible faulty coolant thermistor or connection/wiring fault.
15 Fuel thermistor out of range. Possible faulty coolant thermistor or connection/wiring fault.
17 Throttle pot out of range. Possible faulty throttle potentiometer / incorrect setting or connection/wiring fault.
18 Throttle pot output too high with low airflow. Major air leak between airflow meter and intake plenum. Possible faulty airflow meter or throttle potentiometer or wiring/connections to either.
19 Throttle sensor output too low with high airflow. Possible faulty airflow meter or throttle potentiometer or wiring/connections to either.
21 Tune resistor out of range Tune resistor has become disconnected / damaged.
23 Low fuel pressure. Possible faulty fuel pump/ blocked filter or faulty fuel pressure regulator. VALID FOR CAT CARS ONLY.
25 Misfire at full load. A misfire has been detected while engine under heavy throttle and during high airflow meter readings. Check coil/plugs/leads/ distributor and ignition module. Code means that lambda sensors have detected a rich condition under load. Also see codes 40 and 50. VALID FOR CAT CARS ONLY.
28 Air leak. Air leak around intake plenum. Check all hoses/ injector seals etc.
29 Checksum error. ECU fault. Try resetting ECU and test driving again. If fault code returns ECU may be faulty. NOTE – any other codes generated should be ignored.
34 Fuelling fault in nearside injector bank. For cylinders 1-3-5-7 Possible injector, lambda sensor fault or wiring / connection fault to either. Blocked injector(s) or air leak at injector /inlet manifold. VALID FOR CAT CARS ONLY.
36 Fuelling fault in offside injector bank. For cylinders 2-4-6-8. Possible injector, lambda sensor fault or wiring / connection fault to either. Blocked injector(s) or air leak at injector /inlet manifold. VALID FOR CAT CARS ONLY.
40 Misfire on nearside bank. Misfire on 1-3-5-7 cylinders only. Nearside lambda sensor has detected a fault (or fault in lambda sensor circuit). VALID FOR CAT CARS ONLY
44 Offside lambda sensor out of range. Possible faulty lambda sensor or wiring/connection fault. See section 5 below for check. If in conjunction with code 45 then suspect lambda heater circuit. VALID FOR CAT CARS ONLY
45 Nearside lambda sensor out of range. Possible faulty lambda sensor or wiring/connection fault. See section 5 below for check. If in conjunction with code 44 then suspect lambda heater circuit. VALID FOR CAT CARS ONLY
48 Stepper motor fully open below 500rpm or fully closed above 750rpm. Possible faulty stepper motor or wiring connections. Stepper motor needs cleaning / is jammed. Incorrectly set idle adjustment screw. Incorrectly set throttle butterfly. Misfire or rough running because of other faults.
50 Misfire on offside bank Misfire on 2-4-6-8 cylinders only. Offside lambda sensor has detected a fault (or fault in lambda sensor circuit). VALID FOR CAT CARS ONLY
58 ECU cannot distinguish between codes 23 and 28. Fault maybe either due to code 23 or 28.
59 Same as 58 or fuel thermistor out of range. Documentation seems to vary here. Code either means same as 58, or faulty fuel thermistor or wiring / connector fault.
68 Road speed sensor too low at medium rpm and high airflow. Possible speed sensor or wiring/ connection fault.
88 Power-up check / purge valve fault. Sometimes shown on power up (CAT and NON-CAT CARS ) or could also indicate purge valve fault with carbon canister system. (CAT CARS ONLY)
Thanks Blitz, as always a very detailed reply. I'm always amazed at the knowledge on here.Well, just taken the car for a gentle drive to see if I could get the MIL light back on. Not a flicker !!
Will the light have to be on to get a fault code ? Also is it safe to drive it to the specialist I use to get a diagnosis or should I get it transported.
Blitz, you mentioned it going into 'safe mode'. Will the ecu always do this to protect from serious damage ?
Will the light have to be on to get a fault code ? Also is it safe to drive it to the specialist I use to get a diagnosis or should I get it transported.
Blitz, you mentioned it going into 'safe mode'. Will the ecu always do this to protect from serious damage ?
No, the fault codes are not always accompanied by the MIL light. Any stored fault codes will stay in the ECU until it has been reset (by disconnecting it).
Limp home mode is there to keep the car running without having to rely on any of the sensors, instead of just shutting the injection system down.
Limp home mode is there to keep the car running without having to rely on any of the sensors, instead of just shutting the injection system down.
Pleased to report it was nothing serious. The fuel pressure was set to low after the RR at the Growl. The ecu with the plug and play tornado chip didn't like it. Next step is to book it in with MA to get it set up propeerly. Wonder if he can squeeze another 9.6 BHP out of her to reach my target 300 !! 
Mr MoJo said:
Johno, sorry I missed you yesterday, you were pointed out to me from a distance by Barretti and I meant to come and say hello, but couldn't find you afterwards !!
Sorry I missed you Simon . . . it was a flying visit as I am in the middle of finishing my Dad's Chimaera paint work, doing the final polishing before eh get's back from holiday. The Griff is in his garage in Norfolk as we were servicing it ahead of the European tour and I didn't have the time to go and get it to go to the Growl in it . .It was a bloody expensive trip to the Growl, I somehow managed to spend £710 in 2hrs and £200 of that wasn't even mine . . although I've gotta pay it back
(thanks Ian, you really are a friend)Look out for the continental Griffith meeting . .. have a plan if you fancy taking it for a drive
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