GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 1998 🢒 Trans Sport Ext. 🢒 Body and Accessories 🢒 Wiring Systems 🢒 Scan Tool Does Not Communicate with E and C Data Line

Step

Action

Value(s)

Yes

No

1

Was the entire Data Link Connector (DLC) system check performed?

--

Go to Step 2

Go to Diagnostic System Check - Data Link Communications

2

Use a J 39200 digital multimeter (DMM) in order to measure the voltage between B+ and DLC terminal 5.

Is the voltage within the specified range?

B+ (9-14 V)

Go to Step 3

Go to Step 4

3

Inspect for proper connection of the scan tool to the DLC.

Is the connection OK between the scan tool and the DLC?

--

Go to Step 5

Go to Step 6

4

Repair the poor connection or an open in circuit 1550 between the DLC and S211.

Is the repair complete?

--

Go to Step 18

--

5

Attempt to establish communication with the radio on a different vehicle using the scan tool.

Can communication be established with the scan tool?

--

Go to Step 7

Go to Step 8

6

Repair the poor connection between the DLC terminal 14 and the scan tool.

Is the repair complete?

--

Go to Step 18

--

7
  1. Reconnect the scan tool to the DLC.
  2. Turn the ignition switch to the RUN position.
  3. Use a scan tool in order to re-attempt to establish communication with the radio.

Can the scan tool communicate with the radio?

--

Go to Step 9

Go to Step 10

8

The scan tool may be malfunctioning. Refer to the scan tool instruction manual for additional information.

Is the action complete?

--

Go to Step 18

--

9
  1. The malfunction is intermittent and not present at this time. Inspect CKT 835 and the radio for a poor connection or open, a short to B+ or a short to ground.
  2. Repair as needed.

Is the repair complete?

--

Go to Step 18

--

10
  1. Turn the ignition switch OFF.
  2. Disconnect the radio connector C2.
  3. Use a J 39200 DMM in order to measure the resistance between the DLC terminal 5 and terminal 14.

Is the resistance the same as the specified value?

∞

Go to Step 11

Go to Step 12

11
  1. Turn the ignition switch to the RUN position.
  2. Use a J 39200 DMM in order to measure the voltage between the DLC terminal 5 and terminal 14.

Is the voltage within the specified value?

Less than 1 V

Go to Step 13

Go to Step 14

12

Repair the short to ground in circuit 835.

Is the repair complete?

--

Go to Step 18

--

13

Use a J 39200 DMM in order to measure the resistance between the DLC terminal 14 and the radio harness connector C2 terminal 15.

Is the resistance within the specified value?

0-2ohms

Go to Step 15

Go to Step 16

14
  1. Turn the ignition switch OFF.
  2. Repair the short to B+ in circuit 835.

Is the repair complete?

--

Go to Step 18

--

15
  1. Turn the ignition OFF.
  2. Reconnect the radio.
  3. Turn the ignition switch to the RUN position.
  4. Use a scan tool in order to attempt to establish communication with the radio.

Can the scan tool communicate with the radio?

--

Go to Step 18

Go to Step 17

16

Repair the poor connection or an open in circuit 835.

Is the repair complete?

--

Go to Step 18

--

17

Inspect for power, ground and proper connections to the radio. Refer to Radio/Audio System Check in Entertainment for additional information.

Is the action complete?

--

Go to Step 18

--

18
  1. Ensure that the ignition switch is OFF.
  2. Reconnect the connectors. Reinstall the components.

Is the action complete?

--

Go to Diagnostic System Check - Data Link Communications

--