TPMS inputs and outputs (Discovery 3)

Item name	Spare part number	Description
1	-	Connector C2447
2	-	Connector C1537
3	-	Not used

Two connectors provide an interface between the TPMS module and the external devices of this system. The third connector socket on the TPMS module is not used.

The following tables show the signals and power lines corresponding to each connector pin.

Connector C1537

contact no	Description	Enter exit
1	Not used	-
2	Low speed CAN bus - input	Enter exit
3	High speed CAN bus - input	Enter exit
4	Not used	-
5	TPMS Switch LED Power	Exit
6	Not used	-
7	TPMS switch	Entrance
8	12 V ignition power	Entrance
9	Not used	-
10	Low speed CAN bus - output	Enter exit
11	High speed CAN bus - output	Enter exit
12	Weight	Entrance
13-15	Not used	-
16	Continuous 12 V battery supply	Entrance

Connector C2447

contact no	Description	Enter exit
1-4	Not used	-
5	Left Rear Initiator - Positive (+) signal	Exit
6	Left Rear Initiator - Negative (-) signal	Exit
7	Right Rear Initiator - Positive (+) signal	Exit
8	Right Rear Initiator - Negative (-) signal	Exit
9-12	Not used	-
13	Left front initiator - positive (+) signal	Exit
14	Left Front Initiator - Negative (-) signal	Exit
15	Right front initiator - positive (+) signal	Exit
16	Right Front Initiator - Negative (-) signal	Exit

CAN signals (Controller Area Network - local area network of controllers)

The TPMS module transmits and receives digital messages on the medium speed CAN bus. The received messages are used to control the operation of the TPMS. Messages transmitted contain TPMS status information and commands to turn on indicators and/or display messages on the instrument cluster message center display.

Received messages

The TPMS module accepts the messages listed in the following table.

Message	Transmitter
Vehicle speed	ABS module
Corrected ambient temperature	ATC module
Status of marker lights	CJB
Ignition switch status	CJB
Odometer reading	Dashboard
Timer readings	Dashboard
Vehicle voltage level	Dashboard
Engine crankshaft relay status	ECM
Physical Diagnostic Query	T4
Functional Diagnostic Request	T4
Engine condition	ECM
Basic Vehicle Configuration Identification Information	Dashboard
Vehicle Configuration Options	Dashboard

Transferred messages

The TPMS module sends the messages shown in the following table.

Message	Receiver
TPMS Diagnostic Response	T4
Request to turn on the red TPMS light when the tire pressure drops by 35%.	Dashboard
Request to turn on the yellow TPMS light when the tire pressure drops by 25%	Dashboard
TPMS beep	Dashboard
TPMS message display request	Dashboard