Scan Tool Does Not Communicate with E and C Data Line. Buick Riviera 1999

For 1990-2009 cars only

Makes 🢒 Buick 🢒 1999 🢒 Riviera 🢒 Body and Accessories 🢒 Data Link Communications 🢒 Scan Tool Does Not Communicate with E and C Data Line

Scan Tool Does Not Communicate with E and C Data Line Oldsmobile

Step

Action

Value(s)

Yes

Did you perform the Data Link Communications System Check?

Go to Step 2

Go to Data Link Communications System Check

Connect the scan tool to another vehicle of the same model and year in order to ensure proper operation of the scan tool.
Turn the ignition switch to the RUN position.
Attempt to establish communication with the E and C serial data line.

Does the scan tool communicate with the E and C serial data line?

Go to Step 4

Go to Step 3

•	The scan tool may be malfunctioning.

•	Refer to the scan tool instruction manual.

•	Ensure that the scan tool is functioning.

Does the scan tool operate properly?

Go to Data Link Communications System Check

Connect the scan tool to the original vehicle.
Verify that the scan tool connections are clean and tight.

Is the terminal contact between the data link connector (DLC) terminal 14 and the scan tool OK?

Go to Step 6

Go to Step 5

Repair the terminal contact between the DLC and the scan tool.

Did you complete the repair?

Go to Data Link Communications System Check

Measure the voltage from the data link connector (DLC) terminal 14 to ground.

Does the voltage measure in the specified range?

10-15 V

Go to Step 9

Go to Step 7

Measure the resistance from the data link connector (DLC) terminal 14 to ground.

Does the resistance measure in the specified range?

0-5 ohms

Go to Step 15

Go to Step 8

Repair the open in CKT 835 (DK GRN) between the DLC terminal 14 and S231.

Did you complete the repair?

Go to Data Link Communications System Check

Disconnect the radio.
Measure the voltage from the DLC terminal 14 to ground.

Does the voltage measure in the specified range?

10-15 V

Go to Step 10

Go to Step 16

Disconnect the heater and the A/C programmer.
Measure the voltage from the DLC terminal 14 to ground.

Does the voltage measure in the specified range?

10-15 V

Go to Step 11

Go to Step 18

Is the vehicle equipped with U1S?

Go to Step 12

Go to Step 13

Disconnect the compact disc (CD) player.
Measure the voltage from the DLC terminal 14 to ground.

Does the voltage measure in the specified range?

10-15 V

Go to Step 13

Go to Step 21

Disconnect the heater and A/C control.
Measure the voltage from the DLC terminal 14 to ground.

Does the voltage measure in the specified range?

10-15 V

Go to Step 14

Go to Step 23

Repair the short in CKT 835 (DK GRN).

Did you complete the repair?

Go to Data Link Communications System Check

Disconnect the radio.
Measure the voltage from the DLC terminal 14 to ground.

Does the resistance measure in the specified range?

0-5 ohms

Go to Step 17

Go to Step 16

Replace the radio.

Did you complete the repair?

Go to Data Link Communications System Check

Disconnect the heater and A/C programmer.
Measure the resistance from the DLC terminal 14 to ground.

Does the resistance measure in the specified range?

0-5 ohms

Go to Step 19

Go to Step 18

Replace the heater and A/C programmer.

Did you complete the repair?

Go to Data Link Communications System Check

Is the vehicle equipped with U1S?

Go to Step 20

Go to Step 22

Disconnect the CD player.
Measure the resistance from the DLC terminal 14 to ground.

Does the resistance measure in the specified range?

0-5 ohms

Go to Step 22

Go to Step 21

Replace the CD player.

Did you complete the repair?

Go to Data Link Communications System Check

Disconnect the heater and A/C programmer.
Measure the resistance from the DLC terminal 14 to ground.

Does the resistance measure in the specified range?

0-5 ohms

Go to Step 14

Go to Step 23

Replace the heater and A/C control.

Did you complete the repair?

Go to Data Link Communications System Check

Scan Tool Does Not Communicate with E and C Data Line Buick

Step	Action	Value(s)	Yes	No
1	Did you perform the Data Link Communications System Check?	--	Go to Step 2	Go to Data Link Communications System Check
2	Connect the scan tool to another vehicle of the same model and year in order to ensure proper operation of the scan tool. Turn the ignition switch to the RUN position. Attempt to establish communication with the E and C serial data line. Does the scan tool communicate with the vehicle?	--	Go to Step 4	Go to Step 3
3	The scan tool may be malfunctioning. Refer to the scan tool instruction manual in order to ensure that the scan tool is functioning. Does the scan tool operate properly?	--	Go to Data Link Communications System Check	--
4	Connect the scan tool to the original vehicle. Verify that the scan tool connections are clean and tight. Is the terminal contact between the data link connector (DLC) terminal 14 and the scan tool OK?	--	Go to Step 6	Go to Step 5
5	Repair the terminal contact between the DLC and the scan tool. Did you complete the repair?	--	Go to Data Link Communications System Check	--
6	Measure the voltage from the DLC terminal 14 to ground. Does the voltage measure in the specified range?	10-15 V	Go to Step 9	Go to Step 7
7	Measure the resistance from the DLC terminal 14 to ground. Does the resistance measure in the specified range?	0-5 ohms	Go to Step 15	Go to Step 8
8	Repair the open in CKT 835 (DK GRN) between the DLC terminal 14 and S231. Did you complete the repair?	--	Go to Data Link Communications System Check	--
9	Disconnect the radio. Measure the voltage from the DLC terminal 14 to ground. Is the voltage with the specified range?	10-15 V	Go to Step 10	Go to Step 16
10	Disconnect the heater and A/C programmer. Measure the voltage from the DLC terminal 14 to ground. Does the voltage measure in the specified range?	10-15 V	Go to Step 11	Go to Step 18
11	Is the vehicle equipped with U1S?	--	Go to Step 12	Go to Step 13
12	Disconnect the compact disc (CD) player. Measure the voltage from the DLC terminal 14 to ground. Does the voltage measure in the specified range?	10-15 V	Go to Step 13	Go to Step 21
13	Is the vehicle equipped with the cellular telephone module?	--	Go to Step 14	Go to Step 24
14	Disconnect the cellular telephone module. Measure the voltage from the DLC terminal 14 to ground. Does the voltage measure in the specified range?	10-15 V	Go to Step 24	Go to Step 25
15	Disconnect the radio. Measure the resistance from the DLC terminal 14 to ground. Does the resistance measure in the specified range?	0-5 ohms	Go to Step 17	Go to Step 16
16	Replace the radio. Did you complete the repair?	--	Go to Data Link Communications System Check	--
17	Disconnect the heater and A/C programmer. Measure the resistance from the DLC terminal 14 to ground. Does the resistance measure in the specified range?	0-5 ohms	Go to Step 19	Go to Step 18
18	Replace the heater and A/C programmer. Did you complete the repair?	--	Go to Data Link Communications System Check	--
19	Is the vehicle equipped with U1S?	--	Go to Step 20	Go to Step 22
20	Disconnect the CD player. Measure the resistance from the DLC terminal 14 to ground. Does the resistance measure in the specified range?	0-5 ohms	Go to Step 22	Go to Step 21
21	Replace the CD player. Did you complete the repair?	--	Go to Data Link Communications System Check	--
22	Is the vehicle equipped with the cellular telephone module?	--	Go to Step 23	Go to Step 24
23	Disconnect the cellular telephone module. Measure the resistance from the DLC terminal 14 to ground. Does the resistance measure in the specified range?	0-5 ohms	Go to Step 24	Go to Step 25
24	Repair the in CKT 835 (DK GRN). Did you complete the repair?	--	Go to Data Link Communications System Check	--
25	Replace the cellular telephone module. Did you complete the repair?	--	Go to Data Link Communications System Check	--