This procedure applies to '94-'95 164s


The Motronic M1.7 system uses two different self diagnosis procedures which both allow themost common defects observed when the vehicle is used to be identified:

This troubleshooting is based on the indications of the FLASHING CODE. Each fault is highlighted according to the composition of the fault code. Some faults which may occur within the system can not be recognised by the self diagnosis system within the control unit S11: for this reason supplementary checks are provided for the components which are not controlled by the FLASHING CODE. In general each test should be considered separately and should only be carried out on the component affected. There are the following exceptions:


The Motronic M1.7 control unit is equipped with a built-in auto diagnostic system able to provide the list of the errors memorized during running by the flashing of the CHECK ENGINE warning light located on the instrument panel. Each error code is made up of 4 blocks. The first block of information is made up of short flashes, each of lasts 0.5secs at an interval of 0.5 secs. THE NUMBER OF FLASHES SHOULD BE NOTED. At the end and after pause of approx. 2.5 secs, the second block starts a on for the third and fourth blocks. Obviously, for each the four blocks, the number of flashes must be noted which, at the end, will give a four figure number which represents the fault code which should then be looked up in the attached table. The procedure is the following:

Note the number of flashes in order to identify the error code memorized. Continue the diagnosis on the basis of the indications contained in the attached table relative to the error code that has been identified. If the warning light does not flash, carry out test A to check the supply voltage to control unit S11.
No flash - supply circuit control unit faulty A
4444 No stored faults If it does not start carry out tests Q, R, S
1211 Incorrect battery voltage Restore correct voltage by recharging or replacing the battery
1214 Engine temperature sensor faulty B
1216 Throttle angle sensor faulty C
1221 Air flow meter faulty D
1222 Constant idle speed actuator faulty (opening winding) E
1223 Lambda probe regulation faulty F
1224 Heated lambda probe faulty G
1225 Air temperature sensor faulty H
1226 ECU faulty Replace control unit S11
1231 Electroinjectors faulty I
1232 Electroinjectors faulty I
1233 Constant idle speed actuator faulty (closing winding) E
1235 A/C input signal faulty J
1236 Heater/ventilation system (compressor control faulty) K
1243 Petrol pump relay faulty L
1244 Evaporative solenoid valve faulty M
1251 Eprom control unit faulty Replace control unit S11
1252 Speed sensor faulty N
1254 Throttle angle sensor faulty C
1255 Cam angle sensor faulty 0
2111 Knock sensor 1 faulty p
2112 Knocksensor2 faulty p
2113 Knock regulator faulty (voltage regulator)Replace control unit S11
2116 Knock regulator faulty (voltage regulator)Replace control unit S11
R.p.m. and timing sensor Q
Fuel circuit R
Ignition S
Check communication lines between Electronic automatic gearbox T