1997 Nissan Altima

Hi chrismanges,

Thank you for the donation.

The camshaft position sensor would cause misfiring and the following are test procedures.

DTC P0340 - CAMSHAFT POSITION (CMP) SENSOR

1. Check Ground Circuit - Turn ignition off. Disconnect CMP sensor harness connector. See Fig. 15 . Using an ohmmeter, check continuity between CMP sensor harness connector terminal "a" (Black wire) and ground. See Fig. 16 . If no continuity exists, repair open Black wire. If continuity exists, go to next step.

2. Check Power Supply - Turn ignition on. Using a voltmeter, measure voltage between CMP sensor harness connector terminal "b" (Orange wire) and ground. See Fig. 16 . If battery voltage is present, go to next step. If battery voltage is not present, repair fault in Orange wire circuit.

3. Check Input Signal Circuit - Turn ignition off. Disconnect ECM harness connector. See Fig. 1 . Using an ohmmeter, check continuity between CMP sensor harness connector terminal "c" (Yellow wire) and ECM harness connector terminals No. 41 and 45. See Fig. 3 & Fig. 15 . If no continuity exists, repair fault in Yellow wire as required. If continuity exists, check continuity between CMP harness connector terminal "d" (Blue wire) and ECM harness connector terminals No. 40 and 44. If no continuity exists, repair fault in Blue wire as required. If continuity exists, go to next step.

4. Check Component - Reconnect all harness connectors. Start engine and allow to idle. Set voltmeter on AC scale. Using voltmeter to backprobe CMP harness connector, measure voltage between Yellow wire terminal and Blue wire terminal. If about 2.3 volts are present, go to next step. If about 2.3 volts are not present, replace CMP sensor and perform FINAL CHECK in self diagnostic section.

5. Disconnect ECM wiring harness connector. Check connector pins for damage or corrosion. Check all circuit connectors for clean, tight fit and service if necessary. If fault is still present, replace CMP sensor.