80-17Fault code 31 · Fresh-air blower motor - voltage too low/ too high

911 Turbo (996) Air conditioning H01, H02 80 80-17Fault code 31 Fresh-air blower motor - voltage too low/ too high Diagnostic conditions • Ignition on • Blower switched on Note! ♦No control module fault stored ♦Supply voltage OK. Possible cause of fault ♦Fuse D6 faulty ♦Relay for fresh-air blower faulty ♦Blower regulator (end setting) faulty ♦Fault in the lines between relay for fresh-air blower or blower reg- ulator (end setting) and blower motor. Affected terminals Plug B, terminals 10, 11 and 12 Diagnosis/troubleshooting Work instruction Display OK If not OK 1 Check fuse D6 ⇒ Step 2 Replace fuse. 2 Check relay for fresh-air ♦Switch off ignition Battery voltage Check line between blower ⇒ Step 3 fuse D 6 and relay ♦Remove relay for fresh-air socket for open cir- blower cuit/ short circuit to ♦Switch on ignition ground. ♦Measure voltage at relay socket between pin 3 (terminal 30) and ground ♦Measure voltage at relay socket between pin 3 and pin 2 ♦Measure voltage at relay socket between pin 2 and pin 7 8001 Fault code 31 80-17 page 1 Printed in Germany – 15, 2001 31xxxh02