Development of the Motronic Autodiagnostic Feature

THIS BULLETIN SUPERCEDES SERVICE BULLETIN NO. 419 DATED JUNE, 1991


Development of the Motronic Autodiagnostic feature includes the following improvements:

1. It is possible that all defects detected by the Motronic ECU can be stored in memory simultaneously. In previous models, only five (5) defects could be stored simultaneously.

2. There is a five-second delay in the illumination of the "Check Engine" light if an intermittent fault should occur. Initially the delay was 2.5 seconds.

3. The "Fuel Pump Relay" (code 15) and the "Idle Regulation Valve" (code 22) are now classified as minor defects, and the "Check Engine" light will not illuminate if a fault is detected. Please note that the Model Year 1991 and 1992 XU9J2 engine utilizes an idle regulation valve.

4. The Motronic ECU will now detect a fault in the "Engine Speed Sensor" (code 41). This is classified as a minor defect and will not cause the "Check Engine" light to illuminate.

Attached please find two identification charts which list the codes for the XU9J2 and XU9J4 engines as related to VIN.

We are also including the electrical schematic diagram and component location for the idle regulation electrovalve, which is now equipped on all XU9J2 engines.