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Home >> Porsche >> 1983 >> 944 L4-2479cc 2.5L >> Repair and Diagnosis >> Powertrain Management >> Computers and Control Systems >> Testing and Inspection >> Initial Inspection and Diagnostic Overview >> Diagnostic Strategies >> Test Points >> Test Point 2 - Power Supply for DME Control Unit and Fuel Pump
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Test Point 2 - Power Supply for DME Control Unit and Fuel Pump

TEST POINT 2

Power Supply for DME Control Unit and Fuel Pump


1. DME Control Unit
1.1 Turn off ignition and pull off multiple pin plug on DME control unit.
1.2 Turn on ignition.




1.3 Measure voltage between term. 35 and term. 5 as well as between term. 18 and term. 5.
Specification: battery voltage.
(Always use extra wires to connect tester.)
If voltage deviates from specified value, check fuel pump relay, 9-pin plug connection above brake booster (term. 2 and term. 3) and corresponding wires.
1.4 Turn off ignition and connect multiple pin plug on DME control unit.

2. Fuel Pump
Check the following points, if for example the fuel pump does not run while starting the engine.
2.1 Check fuse 2 (16 amps) in auxiliary fuse box.
2.2 Check fuel pump relay.
2.3 Supply battery voltage to term. 4 of 9-pin plug connection above brake booster, or bridge term. 30 and 87 b on socket of fuel pump relay.
Fuel pump should then run.
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