Work sequence

Fig 1: Identifying Plug

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• Remove plug - arrow  -.

Fig 2: Identifying - Connect pressure tester VAS 5187

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• Connect pressure tester VAS 5187 as shown.
• Start engine and run at idling speed.
• Connect Vehicle diagnosis, Testing and Information System VAS 5051 and select operating mode "Vehicle self-diagnosis". Then select engine control module with Address word "01".
• Press diagnosis function "08-Read measured value block".
• Enter display group "2" using number block and confirm entry with Q key.
• Read engine idling speed in display zone 1.
• Increase engine speed to 1500 rpm.
• Observe pressure indicated on pressure gauge. Specification: min. 3.5 bar
• Press ← key.
• Press function "06-End output".
• Switch off ignition.

If the specification is not obtained:

• Replace tandem pump. Refer to Tandem pump, removing and installing