Bosch Motronic Fault Code Reading Without TAD 4-99

Created: 23. 06. 2003
Updated: --. --. ----

Code Extraction Without The TAD 4-99 Tester

1. Connect a switched jumper to wire 17 of connector M720 which is the green 2 pin connector. Connect the other terminal of the switched jumper to ground.
2. Turn the ignition switch to the "RUN" (ON) position.
3. Close the switched jumper for 3 seconds. The "CHECK ENGINE" indicator will come on.

Open the "switched jumper" and the "CHECK ENGINE" indicator will:

1. Blink once for: 1__ (tens)
2. Remain off for: 1.5 seconds
3. Blink twice for: __2 (units)

Code 12 which indicates the beginning of the "TEST" sequence has been displayed.

1. Wait for the "CHECK ENGINE" light to come on continuously.
2. Close the switched jumper for 3 seconds. The "CHECK ENGINE" indicator will come on.

Open the "switched jumper" and the "CHECK ENGINE" indicator will:

1. Blink (tens)
2. Remain off for: 1.5 seconds
3. Blink (units)

Remember the first set of flash codes is the (tens) and the second set of flash codes is the (units). The combination of the (tens)+(units) is the displayed fault code. Take note of all the stored codes.

1. Repeat steps 4 and 5 until a code 11 is displayed. Up to 5 codes may be stored in the memory. Code 11 indicates the end of the test sequence and there are no other codes stored. Refer to the fault code chart.
2. Repair the indicated faults or repeat the test. Be sure to disconnect the "switched jumper" and turn the ignition switch to the "OFF" position before attempting repairs. Disconnecting components and wiring harness connectors with the ignition switch in the "RUN" (ON) position may set additional codes and cause permanent damage to the Motronic system.
3. To erase the fault code memory turn the ignition switch to the "RUN" (ON) position.
   • Perform a test sequence up to a code 11
   • Depress the switched jumper for more than 10 seconds

The "CHECK ENGINE" indicator should be "ON" and all fault codes should have been cleared.