Nissan Maxima Service and Repair Manual: Wiring diagram 

S connector circuit 

Description  The starter motor magnetic switch is supplied with power when the ignition switch is turned to the START position while the selector lever is in the P or N position. Diagnosis ...

Symptom diagnosis

STARTING SYSTEM Symptom Table ...

Other materials:

P0603 ECM power supply
Description Battery voltage is supplied to the ECM even when the ignition switch is turned OFF for the ECM memory function of the DTC memory, the air-fuel ratio feedback compensation value memory, the idle air volume learning value memory, etc. DTC Logic DTC DETECTION LOGIC DTC CON ...

P0127 IAT sensor
Description The intake air temperature sensor is built-into the mass air flow sensor (1). The sensor detects intake air temperature and transmits a signal to the ECM. The temperature sensing unit uses a thermistor which is sensitive to the change in temperature. Electrical resistance o ...

B2578, B2579 in-vehicle sensor
Description In-vehicle Sensor The in-vehicle sensor (1) is located on instrument lower cover (LH). It converts variations in compartment air temperature drawn from the aspirator into a resistance value. It is then input into the A/C auto amp. In-vehicle Sensor Circuit Aspira ...