P0703-BRAKE SWITCH 2 PERFORMANCE

For a complete wiring diagram Refer to Section 8W.

When Monitored:
Ignition on.
Set Condition:
When the PCM recognizes Brake Switch No.2 voltage is not equal to the applied value at the PCM when Brake Switch No.1 is applied. This could be a normal condition. If this condition is seen repeatedly by the PCM the fault is set. Cruise will not work for the rest of the key cycle.

Possible Causes

(F1) FUSED IGNITION SWITCH OUTPUT CIRCUIT

(B16) BRAKE SWITCH NO.2 SIGNAL CIRCUIT OPEN

(B16) BRAKE SWITCH NO.2 SIGNAL CIRCUIT SHORTED TO BATTERY VOLTAGE

(B16) BRAKE SWITCH NO.2 SIGNAL CIRCUIT SHORTED TO GROUND

(B15) BRAKE SWITCH NO.1 SIGNAL CIRCUIT OPEN

STOP LAMP SWITCH

PCM

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).

Diagnostic Test

1.ACTIVE DTC

NOTE: Make sure the Stop Lamp Switch is adjusted properly before continuing.

NOTE: Make sure the Stop Lamp Switch is properly wired, such as (B15) Brake Switch No.1 and (B16) Brake Switch No.2 Signal circuit are not switched at the harness connector.

Is the DTC Active at this time?

Yes

Go To 2

Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

2.(F1) FUSED IGNITION SWITCH CIRCUIT

Does the test light illuminate brightly?

Yes

Go To 3

Repair the open or short to ground in the (F1) Fused Ignition Switch Output circuit. Inspect the related fuse and repair as necessary.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

3.STOP LAMP SWITCH

Does the resistance change from below 5.0 ohms to open circuit for each circuit check?

Yes

Go To 4

Replace the Stop Lamp Switch.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

4.(B16) BRAKE SWITCH NO.2 SIGNAL CIRCUIT SHORTED TO BATTERY VOLTAGE

Is the voltage above 0 volts?

Yes

Repair the short to battery voltage in the (B16) Brake Switch No.2 Signal circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

Go To 5

5.(B16) BRAKE SWITCH NO.2 SIGNAL CIRCUIT OPEN

Is the resistance below 5.0 ohms?

Yes

Go To 6

Repair the open in the (B16) Brake Switch No.2 Signal circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

6.(B16) BRAKE SWITCH NO.2 SIGNAL CIRCUIT SHORTED TO GROUND

Is the resistance below 5.0 ohms?

Yes

Repair the short to ground in the (B16) Brake Switch No.2 Signal circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

Go To 7

7.(B15) BRAKE SWITCH NO.1 SIGNAL CIRCUIT OPEN

Is the resistance below 5.0 ohms?

Yes

Go To 8

Repair the open in the (B15) Brake Switch No.1 Signal circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

8.PCM

NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.

Were there any problems found?

Yes

Repair as necessary.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

Replace and program the Powertrain Control Module per Service Information.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)