NG 900/9-3 Motronic CEL Flash Codes
The normally aspirated NG900's use a Motronic Engine Management System (EMS). When a Check Engine Light (CEL) shows, it indicates that there is a potential problem with the systems that are responsible for controlling the emmisions of the car. You can take it to the dealer and they will plug it into a computer to establish which part of the system is causing trouble, but if you want to get a rough idea of what the trouble is then you can use the following method.
On the kick panel underneath the steering wheel, and in front of the pedals, you will see a rectangular piece of plastic. This is the socket that the dealer plugs their diagnostic equipment into. Remove the cover and you will see that it has two rows of 8 connectors (See below)
- Get a piece of insulated electrical wire and strip back the insulation about 5mm at each end. Insert one end of the wire into the socket for pin 6 (this is highlighted in red above)
- Find a suitable place on the bodywork that you can ground the other end of the wire too (DO NOT ground it yet!)
- Turn the ignition on and ground the wire for between 0.5 and 4 secs.
- The CEL will now flash in two stages. Count the first set of flashes and then the second set. The two will make up the two digit number that you are looking for. e.g. 4 flashes followed by 1 flash equals 41.
- Refer to the tables below to establish what the code means.
Motronic 2.10.2 (4 Cyl. engines)
Flash code Function 11 Relay, secondary air injection 12 No fault 21 Mass air flow sensor 41 Coolant temperature sensor 51 Throttle position sensor 61 Oxygen sensor 72 Adaptation, long time 73 Adaptation, short time 81 EVAP canister purge valve 91 Control module fault (RAM) 92 Control module fault (ROM)
Motronic 2.8.1 (V6 Engines)
Flash code Function 11 Relay, secondary air injection 12 No fault 21 Mass air flow sensor 31 Intake air temperature sensor 41 Coolant temperature sensor 51 Throttle position sensor 61 Oxygen sensor, Cyl. 1-3-5 62 Oxygen sensor, Cyl. 2-4-6 71 Adaptation, Cyl. 1-3-5 (rich/lean) 72 Adaptation, Cyl. 2-4-6 (rich/lean) 81 EVAP canister purge valve 91 Control module fault (RAM/ROM)