Rear Wiper Operation

WARNING: This page is about a different car, the 2005 Infiniti QX56. However, it is still accessible from the selected car via links, so may be relevant.

When the ignition switch is in the ON or START position, and the rear wiper switch is in the ON position, the BCM detects a rear wiper ON request through the combination switch (wiper switch) reading function.

The BCM will first check the status of the glass hatch ajar switch before supplying power to the rear wiper motor. If the glass hatch ajar switch is closed (ground) the BCM will not turn on the rear wiper motor. If the glass hatch ajar switch is open (not grounded) the BCM will control the rear wiper motor as follows.

The BCM controls rear wiper motor operation by switching direction of current flow between the two rear wiper motor output circuits.

Power is supplied to output circuit 1 for forward operation (counterclockwise sweep),

through BCM terminal 55
to rear wiper motor terminal 4.

Ground is supplied

to rear wiper motor terminal 6
through BCM terminal 54
through BCM terminal 67
through grounds M57, M61 and M79.

With output circuit 1 power and ground supplied, the rear wiper motor operates in a counterclockwise sweep direction until auto stop switch 1 closes (full sweep position). Auto stop switch 1 supplies ground

to BCM terminal 44
through rear wiper motor terminal 2
through rear wiper motor terminal 5
through grounds B117 and B132.

When the BCM receives this ground signal it turns off output circuit 1 and turns on output circuit 2. Power is supplied to output circuit 2 for reverse operation (clockwise sweep),

through BCM terminal 54
to rear wiper motor terminal 6.

Ground is supplied

to rear wiper motor terminal 4
through BCM terminal 55
through BCM terminal 67
through grounds M57, M61 and M79.

With output circuit 2 power and ground supplied the rear wiper motor operates in a clockwise sweep direction until auto stop switch 2 closes (full sweep position). Auto stop switch 2 supplies ground

to BCM terminal 26
through rear wiper motor terminal 1
through rear wiper motor terminal 3
through grounds B117 and B132.

When the BCM receives this ground signal it turns off output circuit 2 and turns on output circuit 1. This process repeats until the rear wiper switch or ignition switch is turned off.

If the ignition switch is turned to OFF during operation, the rear wiper motor will immediately stop. If the ignition switch is turned ON after this condition, and the BCM does not receive a rear wiper switch ON or INT signal, the BCM will operate the rear wiper to the auto stop position.

If the BCM does not receive a change in status in either auto stop switch 1 or auto stop switch 2 within a 5 second period of output circuit 1 or output circuit 2 operation, the BCM will turn off output circuit 1 and output circuit 2.

If the BCM detects the rear door glass ajar signal during rear wiper motor operation, the BCM will operate the rear wiper motor to the auto stop position. Once the rear door glass ajar signal returns to open (not grounded) for 5 or more seconds, the BCM will resume rear wiper motor operation.