P0703-BRAKE SWITCH 2 PERFORMANCE

For a complete wiring diagram, refer to the Wiring Information.

When Monitored:
With the gear selector in drive, vehicle speed above a minimum value, and battery voltage greater than 10.4 volts.
Set Condition:
The PCM detects that the actual state of Brake Signal 1 or Brake Signal 2 does not match the desired state during monitoring. One trip fault.

Possible Causes
(B15) BRAKE SIGNAL 1 CIRCUIT SHORTED TO GROUND
(B16) BRAKE SIGNAL 2 CIRCUIT SHORTED TO VOLTAGE
(F202) FUSED IGNITION SWITCH OUTPUT (RUN-START) CIRCUIT OPEN OR HIGH RESISTANCE
(Z912) GROUND CIRCUIT OPEN OR HIGH RESISTANCE
(B15) BRAKE SIGNAL 1 CIRCUIT OPEN OR HIGH RESISTANCE
(B16) BRAKE SIGNAL 2 CIRCUIT OPEN OR HIGH RESISTANCE
STOP LAMP SWITCH
POWERTRAIN CONTROL MODULE (PCM)

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure)

1. DTC IS ACTIVE

1.	Turn the ignition on.

2.	With the scan tool, monitor the Brake Signal 1 and Brake Signal 2 states while pressing and releasing the brake pedal several times.

Do the Brake Signal states change appropriately as the pedal is pressed and released?

Yes

Perform the INTERMITTENT CONDITION diagnostic procedure. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

Go To 2

2. (B15) BRAKE SIGNAL 1 CIRCUIT

1.	Turn the ignition off.

2.	Disconnect the Stop Lamp Switch harness connector.

3.	Using a 12-volt test light connected to 12 volts, check the (B15) Brake Signal 1 circuit at the Stop Lamp Switch harness connector while pressing and releasing the brake pedal several times.

Does the test light change from illuminated to not illuminated as the brake pedal is pressed and released?

Yes

Go To 3

Go To 4

3. (B16) BRAKE SIGNAL 2 CIRCUIT

1.	Turn the ignition on.

2.	Using a 12-volt test light connected to ground, check the (B16) Brake Signal 2 circuit at the Stop Lamp Switch harness connector while pressing and releasing the brake pedal several times.

Does the test light change from illuminated to not illuminated as the brake pedal is pressed and released?

Yes

Go To 11

Go To 7

4. (Z912) GROUND CIRCUIT OPEN OR HIGH RESISTANCE

1.	Turn the ignition off.

2.	Disconnect the Stop Lamp Switch connector.

3.	Using a 12-volt test light connected to 12 volts, check the (Z912) Ground circuit in the Stop Lamp Switch harness connector.

NOTE: The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.

Is the test light illuminated and bright?

Yes

Go To 5

Repair the open or high resistance in the (Z912) Ground circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

5. (B15) BRAKE SIGNAL 1 CIRCUIT SHORTED TO GROUND

1.	Measure the resistance between ground and the (B15) Brake Signal 1 circuit in the Stop Lamp Switch harness connector.

Is the resistance above 100 Ohms?

Yes

Go To 6

Repair the short to ground in the (B15) Brake Signal 1 circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

6. (B15) BRAKE SIGNAL 1 CIRCUIT OPEN OR HIGH RESISTANCE

1.	Turn the ignition off.

2.	Disconnect the Powertrain Control Module (PCM) C1 harness connector.

3.	Measure the resistance of the (B15) Brake Signal 1 circuit between the Stop Lamp Switch harness connector and the PCM C1 harness connector

Is the resistance below 5.0 Ohms?

Yes

Go To 10

Repair the open or high resistance in the (B15) Brake Signal 1 circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

7. (F202) FUSED IGNITION SWITCH OUTPUT (RUN-START) CIRCUIT OPEN OR HIGH RESISTANCE

1.	Turn the ignition off.

2.	Disconnect the Stop Lamp Switch connector.

3.	Turn the ignition on.

4.	Using a 12-volt test light connected to ground, check the (F202) Fused Ignition Switch Output (Run-Start) circuit in the Stop Lamp Switch harness connector.

NOTE: The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.

Is the test light illuminated and bright?

Yes

Go To 8

Repair the open or high resistance in the (F202) Fused Ignition Switch Output (Run-Start) circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

8. (B16) BRAKE SIGNAL 2 CIRCUIT SHORTED TO VOLTAGE

1.	Measure the voltage of the (B16) Brake Signal 2 circuit in the Stop Lamp Switch harness connector.

Is there any voltage present?

Yes

Repair the short to voltage in the (B16) Brake Signal 2 circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

Go To 9

9. (B16) BRAKE SIGNAL 2 CIRCUIT OPEN OR HIGH RESISTANCE

1.	Turn the ignition off.

2.	Disconnect the Powertrain Control Module (PCM) C1 harness connector.

3.	Measure the resistance of the (B16) Brake Signal 2 circuit between the Stop Lamp Switch harness connector and the PCM C1 harness connector.

Is the resistance below 5.0 Ohms?

Yes

Go To 10

Repair the open or high resistance in the (B16) Brake Signal 2 circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

10. STOP LAMP SWITCH

1.	Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Stop Lamp Switch and the Powertrain Control Module (PCM).

2.	Look for any chafed, pierced, pinched, or partially broken wires.

3.	Look for broken, bent, pushed out or corroded terminals.

4.	Perform any Technical Service Bulletins that may apply.

Were any problems found?

Yes

Repair as necessary.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

Replace the Stop Lamp Switch in accordance with the Service Information.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

11. POWERTRAIN CONTROL MODULE (PCM)

1.	Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Stop Lamp Switch and the Powertrain Control Module (PCM).

2.	Look for any chafed, pierced, pinched, or partially broken wires.

3.	Look for broken, bent, pushed out or corroded terminals.

4.	Perform any Technical Service Bulletins that may apply.

Were any problems found?

Yes

Repair as necessary.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

Replace and program the Powertrain Control Module (PCM) in accordance with the Service Information. (Refer to 08 - Electrical/8E - Electronic Control Modules/MODULE, Powertrain Control - Removal) .
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

P0703-BRAKE SWITCH 2 PERFORMANCE

Possible Causes