KE-Jetronic (CIS-E)KE-Jetronic has a very basic fault diagnosis system. It contains only two codes given by the Knock Sensor system. One indicates a wiring fault (either a bad sensor, or a bad harness), and the other indicates a vacuum fault (a leak in the vacuum system somewhere). While not very explanatory, the codes do give the self-mechanic a good starting point to find errors in his system.
To operate the system, locate the test plug in the engine bay, usually just to the right of the engine, above the transmission. The wire color is either blue or blue/brown, and leads to pin 4 of the Knock Sensor Control Unit. Connect an LED test light between this point and the batter positive (+) terminal. The LED should light when the ignition is switched on, indicating the system is responding. Start the engine and briefly raise the idle to at least 3000rpm. The LED should go out. If not, a fault is stored. To check faults, connect a jumper wire between the same test pin connector and ground (-) for at least three seconds. The light should flash in coded intervals, as seen below. Don't forget, after finding and repairing the fault, to run the test again, because the control unit cannot store more then one code at a time, so if there is both an electrical and vacuum issue, it cannot tell you until you fix one and test again.
|Flashes per interval||Description||Action|
|2||Electrical problem||Check wiring, knock sensor, and knock sensor control unit|
|3||Vacuum leak||Check vacuum lines, intake boot, or faulty control unit|