Description And Operation: Operation

WARNING: This page is about a different car, the 2015 Jeep Renegade. However, it is still accessible from the selected car via links, so may be relevant.

The Trailer Tow Module (TTM) is used to operate the trailer lamps and lighting system in conjunction with the vehicles various module outputs. The TTM monitors CAN bus networks for lighting requests from the Body Control Module and other inputs. The TTM itself is responsible for its own logic, actuation and sensing. The TTM is also responsible for trailer light indicator activation sent from it over the bus to the Instrument Cluster (IC).

Some of the CAN inputs received by the TTM include the following:

vehicle speed
reverse gear
stop lights OFF and ON requests
turn and hazard lights OFF and ON requests.
parking lights
rear for lighting

The TTM assures that these lighting functions are maintained synchronous with the vehicles lighting requests as read on the CAN bus. The TTM then sends the appropriate output OFF or ON signal to the respective trailer lights. The TTM also sends an output signal failure to the IC indicating if the light operation has failed. The IC will then display the appropriate indiction.

Fig 1: Trailer Tow Module Circuit Diagram

Courtesy of CHRYSLER GROUP, LLC

Left side direction indicator (21 W)
Rear fog light (2x21 W)
Trailer light ground.
Right side direction indicator (21 W)
Left side light/number plate light (6x5 W)
Brake light (4x21 W)
Left side light/number plate light (6x5 W)
Reversing light (2x21)
+ Battery power supply
Ignition-operated supply
Ground for tow hook socket
Ground for tow hook socket.

H1 - Right side direction indicator control (from Body Control Module/BCM)
H2 - Left side direction indicator control (from BCM)
H3 - Third brake light control (from BCM)
M1 - Side direction indicator on left side door mirror.
M2 - Side direction indicator on right side door mirror.
S1 - third brake light.

Fig 2: Trailer Tow Module Circuit Diagram (NAFTA Market)

Courtesy of CHRYSLER GROUP, LLC

Light ground on trailer
Side light/side marker/number plate light (12x5 W)
Left side brake light/direction indicator (2x21 W)
Right side brake light/direction indicator (2x21 W)

H1 - Right side direction indicator control (from BCM)
H2 - Left side direction indicator control (from BCM)
H3 - Third brake light control (from BCM)
M1 - Side direction indicator on left side door mirror.
M2 - Side direction indicator on right side door mirror.
S1 - Third brake light.