No.7 BRAKE SYSTEM WARNING LIGHT DOES NOT ILLUMINATE/STAYS ON[INSTRUMENT CLUSTER (AJ (3.0L Duratec))]

id0902h7823800

STEP

INSPECTION

ACTION

1

VERIFY BRAKE SYSTEM WARNING LIGHT STATUS

Release the parking brake.

Turn the ignition switch to the ON position.

Does the brake system warning light illuminate for 3 s and then go out?

Yes

The system is normal.

No

Go to the next step.

2

INSPECT PARKING BRAKE SWITCH OPERATION

Turn the ignition switch to the ON position.

Apply the parking brake and inspect the brake system warning light.

Does the brake system warning light illuminate when applying the parking brake?

Yes

Go to Step 10 with the brake system warning light illuminated.

No

If the brake system warning light does not go out, go to the next step.

3

INSPECT PARKING BRAKE SIGNAL CIRCUIT

Disconnect the parking brake switch connector.

Connect a jumper wire (with 10 A fuse) between parking brake switch terminal A (harness-side) and ground.

Turn the ignition switch to the ON position.

Does the brake system warning light illuminate?

Yes

Replace the parking brake switch. Inspect the system for normal operation.

No

Go to the next step.

4

INSPECT FOR OPEN CIRCUIT

Turn the ignition switch to the ON position.

Disconnect the instrument cluster connector.

Measure the resistance between instrument cluster terminal 1B (harness-side) and parking brake switch terminal A (harness-side).

Is the resistance less than 5 ohms?

Yes

Connect the parking brake switch connector. Go to the next step.

No

Repair or replace the wiring harness. Inspect the system for normal operation.

5

INSPECT BRAKE FLUID LEVEL SIGNAL CIRCUIT

Connect the instrument cluster connector.

Disconnect the brake fluid level sensor connector.

Connect a fused jumper wire between brake fluid level sensor terminal B (harness-side) and ground.

Turn the ignition switch to the ON position.

Does the brake system warning light illuminate?

Yes

Go to the next step.

No

Go to Step 8.

6

INSPECT BRAKE FLUID LEVEL SWITCH GROUND CIRCUIT

Turn the ignition switch off.

Measure the resistance between brake fluid level sensor terminal A (harness-side) and ground.

Is the resistance less than 5 ohms?

Yes

Go to the next step.

No

Repair or replace the wiring harness. Inspect the system for normal operation.

7

INSPECT BRAKE FLUID LEVEL SENSOR

Turn the ignition switch off.

Measure the resistance between brake fluid level sensor terminals A (part-side) and B (part-side) under the following conditions.

•  Brake fluid: empty

•  Brake fluid: full

Is the resistance less than 5 ohms with no brake fluid and more than 10,000 ohms when full?

Yes

Go to the next step.

No

Replace the brake fluid level sensor. Inspect the system for normal operation.

8

INSPECT FOR OPEN CIRCUIT

Disconnect the instrument cluster connector.

Turn the ignition switch off.

Measure the resistance between instrument cluster terminal 3N (harness-side) and brake fluid level sensor terminal B (harness-side).

Is the resistance less than 5 ohms?

Yes

Go to the next step.

No

Repair or replace the wiring harness. Inspect the system for normal operation.

9

INSPECT FOR SHORT TO POWER SUPPLY

Turn the ignition switch to the ON position.

Measure the voltage between instrument cluster terminals 1B and 3N (harness-side).

Is there voltage?

Yes

Repair or replace the wiring harness. Inspect the system for normal operation.

No

Go to Step 17.

10

INSPECT PARKING BRAKE SWITCH OPERATION

Disconnect the parking brake switch connector.

Turn the ignition switch to the ON position.

Inspect the brake system warning light.

Does the brake system warning light illuminate?

Yes

Go to the next step.

No

Replace the parking brake switch. Inspect the system for normal operation.

11

INSPECT FOR SHORT TO GROUND

Turn the ignition switch off.

Measure the resistance between instrument cluster terminal 3N (harness-side) and ground.

Is the resistance less than 5 ohms?

Yes

Repair or replace the wiring harness. Inspect the system for normal operation.

No

Go to the next step.

12

INSPECT BRAKE FLUID LEVEL SENSOR

Disconnect the brake fluid level sensor connector.

Turn the ignition switch to the ON position.

Inspect the brake system warning light.

Does the brake system warning light illuminate?

Yes

Go to the next step.

No

Refer to Section 04.

13

INSPECT FOR SHORT TO GROUND

Turn the ignition switch off.

Measure the voltage between instrument cluster terminal 1B (harness-side) and ground.

Is the resistance less than 5 ohms?

Yes

Repair or replace the wiring harness. Inspect the system for normal operation.

No

Go to the next step.

14

INSPECT ABS HU/CM OPERATION

Turn the ignition switch off.

Measure the resistance between instrument cluster terminal 1E (harness-side) and ground.

Is the resistance less than 5 ohms?

Yes

Go to Step 17.

No

Go to the next step.

15

INSPECT FOR OPEN CIRCUIT

Disconnect the ABS HU/CM connector.

Measure the resistance between ABS HU/CM terminal H (harness-side) and instrument cluster terminal 1E (harness-side).

Is the resistance less than 5 ohms?

Yes

Go to the next step.

No

Repair or replace the wiring harness. Inspect the system for normal operation.

16

INSPECT POWER SUPPLY

Turn the ignition switch to the ON position.

Measure the voltage between ABS HU/CM terminal H (harness-side) and ground.

Is there voltage?

Yes

Repair or replace the wiring harness. Inspect the system for normal operation.

No

Refer to Section 04.

17

INSPECT INSTRUMENT CLUSTER OPERATION

Disconnect all the instrument cluster connectors.

Inspection:

•  Corrosion

•  Terminal separation

Connect the instrument cluster connector and verify that its position is correct.

Operate the system and inspect for any malfunction.

Is any malfunction still present?

Yes

Replace the instrument cluster. Inspect the system for normal operation.

No

The system operates normally. The malfunction may result from loose connectors or corrosion. Clear the DTC. Repeat the self-test.

STEP	INSPECTION		ACTION
1	VERIFY BRAKE SYSTEM WARNING LIGHT STATUS Release the parking brake. Turn the ignition switch to the ON position. Does the brake system warning light illuminate for 3 s and then go out?	Yes	The system is normal.
1		No	Go to the next step.
2	INSPECT PARKING BRAKE SWITCH OPERATION Turn the ignition switch to the ON position. Apply the parking brake and inspect the brake system warning light. Does the brake system warning light illuminate when applying the parking brake?	Yes	Go to Step 10 with the brake system warning light illuminated.
2		No	If the brake system warning light does not go out, go to the next step.
3	INSPECT PARKING BRAKE SIGNAL CIRCUIT Disconnect the parking brake switch connector. Connect a jumper wire (with 10 A fuse) between parking brake switch terminal A (harness-side) and ground. Turn the ignition switch to the ON position. Does the brake system warning light illuminate?	Yes	Replace the parking brake switch. Inspect the system for normal operation.
3		No	Go to the next step.
4	INSPECT FOR OPEN CIRCUIT Turn the ignition switch to the ON position. Disconnect the instrument cluster connector. Measure the resistance between instrument cluster terminal 1B (harness-side) and parking brake switch terminal A (harness-side). Is the resistance less than 5 ohms?	Yes	Connect the parking brake switch connector. Go to the next step.
4		No	Repair or replace the wiring harness. Inspect the system for normal operation.
5	INSPECT BRAKE FLUID LEVEL SIGNAL CIRCUIT Connect the instrument cluster connector. Disconnect the brake fluid level sensor connector. Connect a fused jumper wire between brake fluid level sensor terminal B (harness-side) and ground. Turn the ignition switch to the ON position. Does the brake system warning light illuminate?	Yes	Go to the next step.
5		No	Go to Step 8.
6	INSPECT BRAKE FLUID LEVEL SWITCH GROUND CIRCUIT Turn the ignition switch off. Measure the resistance between brake fluid level sensor terminal A (harness-side) and ground. Is the resistance less than 5 ohms?	Yes	Go to the next step.
6		No	Repair or replace the wiring harness. Inspect the system for normal operation.
7	INSPECT BRAKE FLUID LEVEL SENSOR Turn the ignition switch off. Measure the resistance between brake fluid level sensor terminals A (part-side) and B (part-side) under the following conditions. • Brake fluid: empty • Brake fluid: full Is the resistance less than 5 ohms with no brake fluid and more than 10,000 ohms when full?	Yes	Go to the next step.
7		No	Replace the brake fluid level sensor. Inspect the system for normal operation.
8	INSPECT FOR OPEN CIRCUIT Disconnect the instrument cluster connector. Turn the ignition switch off. Measure the resistance between instrument cluster terminal 3N (harness-side) and brake fluid level sensor terminal B (harness-side). Is the resistance less than 5 ohms?	Yes	Go to the next step.
8		No	Repair or replace the wiring harness. Inspect the system for normal operation.
9	INSPECT FOR SHORT TO POWER SUPPLY Turn the ignition switch to the ON position. Measure the voltage between instrument cluster terminals 1B and 3N (harness-side). Is there voltage?	Yes	Repair or replace the wiring harness. Inspect the system for normal operation.
9		No	Go to Step 17.
10	INSPECT PARKING BRAKE SWITCH OPERATION Disconnect the parking brake switch connector. Turn the ignition switch to the ON position. Inspect the brake system warning light. Does the brake system warning light illuminate?	Yes	Go to the next step.
10		No	Replace the parking brake switch. Inspect the system for normal operation.
11	INSPECT FOR SHORT TO GROUND Turn the ignition switch off. Measure the resistance between instrument cluster terminal 3N (harness-side) and ground. Is the resistance less than 5 ohms?	Yes	Repair or replace the wiring harness. Inspect the system for normal operation.
11		No	Go to the next step.
12	INSPECT BRAKE FLUID LEVEL SENSOR Disconnect the brake fluid level sensor connector. Turn the ignition switch to the ON position. Inspect the brake system warning light. Does the brake system warning light illuminate?	Yes	Go to the next step.
12		No	Refer to Section 04.
13	INSPECT FOR SHORT TO GROUND Turn the ignition switch off. Measure the voltage between instrument cluster terminal 1B (harness-side) and ground. Is the resistance less than 5 ohms?	Yes	Repair or replace the wiring harness. Inspect the system for normal operation.
13		No	Go to the next step.
14	INSPECT ABS HU/CM OPERATION Turn the ignition switch off. Measure the resistance between instrument cluster terminal 1E (harness-side) and ground. Is the resistance less than 5 ohms?	Yes	Go to Step 17.
14		No	Go to the next step.
15	INSPECT FOR OPEN CIRCUIT Disconnect the ABS HU/CM connector. Measure the resistance between ABS HU/CM terminal H (harness-side) and instrument cluster terminal 1E (harness-side). Is the resistance less than 5 ohms?	Yes	Go to the next step.
15		No	Repair or replace the wiring harness. Inspect the system for normal operation.
16	INSPECT POWER SUPPLY Turn the ignition switch to the ON position. Measure the voltage between ABS HU/CM terminal H (harness-side) and ground. Is there voltage?	Yes	Repair or replace the wiring harness. Inspect the system for normal operation.
16		No	Refer to Section 04.
17	INSPECT INSTRUMENT CLUSTER OPERATION Disconnect all the instrument cluster connectors. Inspection: • Corrosion • Terminal separation Connect the instrument cluster connector and verify that its position is correct. Operate the system and inspect for any malfunction. Is any malfunction still present?	Yes	Replace the instrument cluster. Inspect the system for normal operation.
17		No	The system operates normally. The malfunction may result from loose connectors or corrosion. Clear the DTC. Repeat the self-test.