For 1990-2009 cars
Body Control Module Components
Cell 51: Fuel Tank Module, Instrument Cluster and Passlock ™ Cylinder

### Circuit Description

This is the fault code (current and history) that is set when the body control module (BCM) detects a short to the battery or an open at the BCM fuel sensor input.

The BCM cannot differentiate between an open or a short to the battery.

### Conditions for Setting the DTC

All of the following conditions must be met:

• | Ignition 0 is active.

• | The analog fuel input is open or shorted to voltage for 2.55 seconds.

### Action Taken When the DTC Sets

• | The fuel gauge displays empty.

• | The low fuel indicator illuminates.

• | Stores DTC P0463 in the BCM memory

### Conditions for Clearing the DTC

• | The BCM goes to sleep and reinitializes with the fault cleared.

• | All the BCM history codes will be cleared after 100 ignition cycles (from OFF to RUN) with no current codes active during the 100 ignition cycles.

• | Use the scan tool.

### Diagnostic Aids

If the DTC is a history DTC, the problem may be intermittent. Perform the above tests while wiggling the wiring and connectors. This may often cause the malfunction to appear.

### Test Description

The numbers below refer to the numbers on the diagnostic table.

1. This step determines if the body control module (BCM) is reading the fuel level sensor.

2. This step determines if there is an open in CKT 470 between the fuel tank module and the left IP wiring harness junction block.

3. This step determines if there is an open in CKT 470 within the left IP wiring harness junction block.

4. This step determines if there is an open in CKT 470 between the left IP wiring harness junction block and the BCM.

5. This step determines if there is a short to the battery in CKT 470 between the left IP wiring harness junction block and the fuel tank module.

6. This step determines if there is a short to the battery within the left IP wiring harness junction block.

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
Important: A short to ground will cause an open fuse(s). Before performing this diagnostic procedure, inspect the fuse(s) for an open.
1 | Was the BCM System Check performed? | -- | Go to Step 2 | Go to Body Control Module System Check
2 |

1. Disconnect the BCM connector C2 terminal A4 CKT 470.
2. Disconnect the fuel tank senderconnector.
3. Use the J 39200 in order to measure the voltage in CKT 470 between the BCM connector C2 terminal A4 and ground.

Does the measured voltage equal the specified value?

0 V

Go to Step 3

Go to Step 8

3 |

1. Back out the left IP wiring harness junction block connector C3 terminal A12 CKT 470.
2. Use the J 39200 DMM in order to measure the resistance in CKT 470 between the fuel tank sender connector terminal D and the left IP wiring harness junction block connector C3 terminal A12.

Is the measured resistance within the specified range?

0-2 ohms

Go to Step 5

Go to Step 4

4 | Repair the open in CKT 470 between the fuel tank sender connector terminal D and the left IP wiring harness junction block connector C3 terminal A12. Is the repair complete? | -- | Go to Step 16 | --
5 |

1. Back out the left IP wiring harness junction block connector C2 terminal A1 CKT 470.
2. Use the J 39200 DMM in order to measure the resistance in CKT 470 between the left IP wiring harness junction block connector C2 terminal A1 and the left IP wiring harness junction block connector C3 terminal A12.

Is the measured resistance within the specified range?

0-2 ohms

Go to Step 6

Go to Step 12

6 | Use the J 39200 DMM in order to measure the resistance in CKT 470 between the left IP wiring harness junction block connector C2 terminal A1 and the BCM connector C2 terminal A4. Is the measured resistance within the specified range? | 0-2 ohms | Go to Step 13 | Go to Step 7
7 | Repair the open in CKT 470 between the left IP wiring harness junction block connector C2 terminal A1 and the BCM connector C2 terminal A4. Is the repair complete? | -- | Go to Step 16 | --
8 |

1. Back out the left IP wiring harness junction block connector C3 terminal A12 CKT 470.
2. Use the J 39200 DMM in order to measure the voltage in CKT 470 of the left IP wiring harness junction block connector C3 terminal A12 and ground.

Does the measured voltage equal the specified value?

0 V

Go to Step 10

Go to Step 9

9 | Repair the short to B+ in CKT 470 between the fuel tank sender connector terminal D and the left IP wiring harness junction block connector C3 terminal A12. Is the repair complete? | -- | Go to Step 16 | --
10 |

1. Disconnect the left IP wiring harness junction block connector C2 terminal A1.
2. Use the J 39200 DMM in order to measure the voltage in CKT 470 of the left IP wiring harness junction block connector C2 terminal A1 and ground.

Does the measured voltage equal the specified value?

0 V

Go to Step 12

Go to Step 11

11 | Repair the short to B+ in CKT 470 between the left IP wiring harness junction block connector C2 terminal A1 and the BCM connector C2 terminal A4. Is the repair complete? | -- | Go to Step 16 | --
12 | Replace the left IP wiring harness junction block. Is the repair complete? | -- | Go to Step 16 | --
13 |

1. Reconnect all the components.
2. Replace the fuel tank sender.

Is the repair complete?

--

Go to Step 14

--

14 | Clear the DTCs from the memory. Does DTC P0463 remain current? | -- | Go to Step 15 | Go to Step 16
15 | Replace the BCM. Refer to the following procedures:

• | Body Control Module (BCM) Programming/RPO Configuration

• | Body Control Module Replacement

Is the repair complete?

--

Go to Step 16

--

16 | Clear the DTCs from the memory. Are the DTCs cleared from the memory? | -- | Go to Body Control Module System Check | --