DME 7.8 DME 7.8 0 · 0-122.5P1142

DME 7.8 DME 7.8 0 0-122.5P1142 Oxygen Sensing Error by means of Short Test, Bank 1 – Above Limit Diagnosis conditions • Mixture adaptation performed with the Porsche System Tester 2 Possible fault cause ♦Incorrect signal from MAF sensor ♦Intake air system leaking ♦Fuel pressure too low ♦Volume supply of fuel pump too low ♦Fuel injectors fouled Affected terminals - Diagnosis/Troubleshooting Note! Air leaks ahead of the oxygen sensors can lead to a fault in adaptation Check exhaust system for leaks. Work instruction Display OK If not OK 1 Check signal from MAF ♦Connect special tool 9637. 0.9 to 1.1 V. Replace MAF sensor sensor. ♦Measure voltage at pin III/23 and ground ♦Switch on the ignition. ♦Start the engine. Approx. 1.4 V 2 Check exhaust system for leaks 3 Check for air leaks in intake air system 4 Check fuel pressure 2469 P1142 0-122.5 page 1 Printed in Germany – 6, 2002 p1142