Check Input Signal Circuit

Turn ignition off. Disconnect ECM harness connector and A/T control unit harness connector. See Figure and Fig 1 . Ensure continuity exists between following terminals:

• A/T control unit connector terminal No. 10 (Brown/Red wire) and ECM connector terminal No. 42 (Brown/Red wire).
• A/T control unit connector terminal No. 11 (Blue/Red wire) and ECM connector terminal No. 44 (Blue/Red wire).
• A/T control unit connector terminal No. 12 (Brown/White wire) and ECM connector terminal No. 12 (Brown/White wire).

See Fig 2 . If continuity is present, perform FINAL CHECK  in this article. If continuity is not present, check connectors between ECM and A/T control unit. Repair harness or connectors as necessary and perform FINAL CHECK  in this article.

Fig 1: Locating A/T Control Unit Connector (Altima)

Courtesy of NISSAN MOTOR CO., U.S.A.

Fig 2: DTC 54, Checking Input Signal Circuit (Altima)

Courtesy of NISSAN MOTOR CO., U.S.A.