GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 1997 🢒 Corvette 🢒 Body and Accessories 🢒 Lighting Systems 🢒 Backup Lamps Inoperative

Backup Lamps Inoperative

Step

Action

Value(s)

Yes

No

1

Were you sent here from the Backup Lamps Diagnostic System Check?

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Go to Backup Lamps Diagnostic System Check

Go to Step 2

2

Perform the Body Control Module Diagnostic System Check?

Are any DTCs stored in memory?

--

Go to applicable table

Go to Step 3

3
  1. Remove the PERIM LP Micro Relay #38.
  2. Set the park brake.
  3. Turn the ignition switch to the ON position.
  4. Move the transmission shift lever into reverse gear.
  5. Connect a DMM between the PERIM LP Micro Relay #38 terminal 87A in the underhood electrical center and ground.
  6. Measure the voltage at terminal 87A which is used for the PERIM LP Micro Relay #38.

Is the voltage within the specified values?

10.0-14.0V

Go to Step 16

Go to Step 4

4
  1. Disconnect the back up lamp switch (manual) connector or the park neutral position switch (auto) connector.
  2. Connect the DMM between the back up lamp switch (manual) connector terminal A or the park neutral position switch (auto) connector C1 terminal B and ground.
  3. Measure the voltage at the back up lamp switch (manual) connector terminal A or the park neutral position switch (auto) connector C1 terminal B.

Is the voltage within the specified values?

10.0-14.0V

Go to Step 13

Go to Step 5

5

Check the BTSI/BU Minifuse® #11.

Is the fuse open?

--

Go to Step 8

Go to Step 6

6
  1. Remove the BTSI/BU Minifuse® #11 from the instrument panel electrical center.
  2. Connect a DMM between the instrument panel electrical center terminal A used for the BTSI/BU Minifuse® #11 and ground.
  3. Measure the voltage at the instrument panel electrical center terminal A used for the BTSI/BU Minifuse® #11.

Is the voltage within the specified values?

10.0-14.0V

Go to Step 7

Refer to Power Distribution

7

Repair the open in CKT 443.

Is the repair complete?

--

Go to Backup Lamps Diagnostic System Check

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8
  1. Back up lamp switch (manual) or park neutral position switch (auto) connector still disconnected.
  2. Remove the BTSI/BU Minifuse® #11 from the instrument panel electrical center.
  3. PERIM LP Micro Relay #38 is removed from the underhood electrical center.
  4. Connect the DMM between the back up lamp switch (manual) connector terminal A or the park neutral position switch (auto) connector C1 terminal B and ground.
  5. Measure for continuity to ground at the back up lamp switch (manual) connector terminal A or the park neutral position switch (auto) connector C1 terminal B.

Is CKT 443 shorted to ground?

--

Go to Step 9

Go to Step 10

9

Repair the short to ground in CKT 443.

Is the repair complete?

--

Go to Backup Lamps Diagnostic System Check

--

10
  1. Connect the DMM between the back up lamp switch (manual) connector terminal B or the park neutral position switch (auto) connector C1 terminal F and ground.
  2. Measure for continuity to ground at the back up lamp switch (manual) connector terminal B or the park neutral position switch (auto) connector C1 terminal F.

Is CKT 1524 shorted to ground?

--

Go to Step 11

Go to Step 12

11

Repair the short to ground in CKT 1524.

Is the repair complete?

--

Go to Backup Lamps Diagnostic System Check

--

12

Repair a short to ground in CKT 24.

Is the repair complete?

--

Go to Backup Lamps Diagnostic System Check

--

13
  1. Position a jumper wire between:
    2. • the back up lamp (manual) switch connector terminal A and terminal B.
    • the park neutral position (auto) switch connector C1 terminal B and terminal F.
  2. Connect a DMM between the PERIM LP Micro Relay Connector terminal 87A and ground.
  3. Measure the voltage at the PERIM LP Micro Relay Connector terminal 87A in the underhood electrical center.

Is the voltage within the specified values?

10.0-14.0V

Go to Step 15

Go to Step 14

14

Repair the open in CKT 1524.

Is the repair complete?

--

Go to Backup Lamps Diagnostic System Check

--

15

Replace the back up lamp switch (manual) or the park neutral position switch (auto).

Is the repair complete?

--

Go to Backup Lamps Diagnostic System Check

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16
  1. Remove the PERIM LP Micro Relay #38.
  2. Install another jumper wire between the terminal 87A and terminal 30 at the underhood electrical center.

Do the backup lamps illuminate?

--

Go to Step 17

Go to Step 18

17

Replace the PERIM LP Micro Relay #38.

Is the repair complete?

--

Go to Backup Lamps Diagnostic System Check

--

18
  1. Disconnect the LH back up lamp connector.
  2. Measure the resistance between the underhood electrical center terminal 30 and the LH back up lamp LH connector terminal A.

Is the resistance within the specified range?

0-3ohms

Go to Step 20

Go to Step 19

19

Repair the open in CKT 24.

Is the repair complete?

--

Go to Backup Lamps Diagnostic System Check

--

20
  1. Disconnect the LH back up lamp connector.
  2. Connect a DMM between the LH back up lamp Underhood Electrical connector terminal G and ground.
  3. Measure the resistance between the LH back up lamp Underhood Electrical connector terminal G and ground.

Is the resistance within the specified range?

0-3ohms

Go to Step 22

Go to Step 21

21

Repair the open in CKT 150 from the backup lamps to G401.

Is the repair complete?

--

Go to Backup Lamps Diagnostic System Check

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22

Replace both backup lamp bulbs.

Is the repair complete?

--

Go to Backup Lamps Diagnostic System Check

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