| Test voltage supply of engine control unit |
| Special tools and workshop equipment required |
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| Handheld multimeter, e.g. -V.A.G 1526 A - |
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| Test box -V.A.G 1598/22- |
Note | For checking the voltage supply of the engine control unit see also → Chapter, display group 005, display field 2. |
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| Fuse for engine control unit O.K |
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| Battery voltage at least 11 V. |
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| Connect the test box -V.A.G 1598/22 - to the wiring loom of the engine control unit → Chapter. |
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| Connect multimeter for voltage measurement to bush 1 (positive via ignition) and earth. |
| Specified value: approx. battery voltage. |
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| If the specified value is not reached, check the cable connection of contact 1 of the engine control unit for interruption according to current flow diagram, if necessary repair → Current flow diagrams and Fitting locations. |
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| If the specified value is not reached, connect the voltage tester to bush 1 of the plug from the engine control unit (positive via ignition) and bush 2 of the plug from the engine control unit (earth supply of the engine control unit). |
| Specified value: approx. battery voltage. |
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| Connect multimeter for voltage measurement to bush 3 (permanent positive) and earth. |
| Specified value: approx. battery voltage. |
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| If the specified value is not reached, check the cable connection of contact 3 of the plug from the engine control unit and electrical centre for continuity according to current flow diagram, if necessary eliminate open circuit → Current flow diagrams and Fitting locations. |
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