OBD-II Data Link Connector

OBD-II Data Link Connector

16 pin OBD-II DLC with terminal identified

All OBD-II vehicles use a 16 pin connector that includes:

Pin 4 - Chassis ground

Pin 5 - Signal ground

Pin 16 - Battery power (4A max.)

GENERAL MOTORS VEHICLES

-SAE J-1850 (VPW, Class 2, 10.4 Kbs) standard, which uses pins 2, 4, 5, and 16, but not 10

-GM Domestic OBD-II

Pin 1 and 9: CCM (comprehensive component monitor)

slow baud rate, 8,192 UART

Pins 2 and 10: OEM enhanced, fast rate, 40,500 baud rate

Pins 7 and 15: generic OBD-II, ISO 9141, 10,400 baud rate

Pins 6 and 14: GMLAN

ASIAN, CHRYSLER, AND EUROPEAN VEHICLES

-ISO 9141-2 standard, which uses pins 4, 5, 7, 15, and 16

-Chrysler Domestic Group OBD-II

Pins 2 and 10: CCM

Pins 3 and 14: OEM enhanced, 60,500 baud rate

Pins 7 and 15: generic OBD-II, ISO 9141, 10,400 baud rate

FORD VEHICLES

-SAE J-1850 (PWM, 41.6 Kbs) standard, which uses pins 2, 4, 5, 10, and 16

-Ford Domestic OBD-II

Pins 2 and 10: CCM

Pins 6 and 14: OEM enhanced, Class C, 40,500 baud rate

Pins 7 and 15: generic OBD-II, ISO 9141, 10,400 baud rate

Schematic of Chevrolet Equinox shows that the vehicle uses a GMLAN BUS (DLC pins 6 & 14) plus a Class 2 (pin 2) and UART

SUMMARY

1. The use of a network for module communications reduces the number of wires and connections needed.

2. Module communication configurations include ring link, star link, and ring/star hybrid systems.

3. The SAE communication classifications for vehicle communications systems include Class A (low speed), Class B (medium speed), and Class C (high speed).

4. Various module communications used on General Motors vehicles include UART, E & C, Class 2, keyword communications, and GMLAN (CAN).

5. Types of module communications used on Ford vehicles include SCP, UBP, and CAN.

6. Chrysler brand vehicles use SCI, CCD, PCI, and CAN communications protocols.

7. Many European vehicles use an underhood electrical connector that can be used to access electrical components and modules using a breakout box (BOB) or special tester.

8. Diagnosis of network communications includes checking the terminating resistors and checking for changing voltage signals at the DLC.

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