GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

  1. Turn the ignition to the OFF position.
  2. Disconnect the cellular telephone module connector from the cellular telephone handset interface.
  3. Turn the ignition to the RUN position.
  4. Use a J 39200 digital multimeter (DMM) set to DC scale in order to measure the voltage between the cellular telephone module connector terminals A and M.

Is battery voltage present?

B+

Go to Step 3

Go to Step 2

2

Use a J 39200 DMM in order to measure the voltage between the cellular telephone module connector terminals M and B.

Is voltage present?

--

Go to Step 5

Go to Step 4

3

Repair the short to ground in CKT 1154 (DK BLU). Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Cellular Telephone System Check

--

4

Use the J 39200 DMM set to OHMS scale in order to inspect for continuity between the cellular telephone module connector terminal M and the cellular telephone handset connector  terminal 2.

Is there continuity?

--

Go to Step 6

Go to Step 7

5

Repair the short to voltage in CKT 1154 (DK BLU). Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Cellular Telephone System Check

--

6

Replace the handset cord with a known good cord.

Is the earpiece sound restored?

--

Go to Cellular Telephone System Check

Go to Step 8

7

Repair the open in CKT 1154 (DK BLU). Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Cellular Telephone System Check

--

8

Is the cellular telephone portable?

--

Go to Step 9

Go to Step 10

9

Replace the cellular telephone handset interface-to-harness connector jumper with a known good part.

Is the earpiece sound restored?

--

Go to Cellular Telephone System Check

Go to Step 11

10

Replace the handset with a known good handset.

Is the earpiece sound restored?

--

Go to Cellular Telephone System Check

Go to Step 12

11

Replace the cellular telephone handset interface with a known good part.

Is the earpiece sound restored?

--

Go to Cellular Telephone System Check

Go to Step 13

12

  1. Inspect all of the connectors for proper terminal contact.
  2. If OK, replace the cellular telephone module.

Is the repair complete?

--

Go to Cellular Telephone System Check

--

13

Replace the cellular telephone handset interface.

Is the repair complete?

--

Go to Cellular Telephone System Check

--