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DTC P0703 [L3 Turbo]

id0102b7809900

DTC P0703 | Brake switch No.1 circuit malfunction
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DETECTION CONDITION | • PCM monitors changes in the input voltage from the brake switch. If the PCM does not detect the voltage change while alternately accelerating and decelerating 8 times, the PCM determines that the brake switch circuit has a malfunction. Diagnostic support note • This is a continuous monitor (CCM). • MIL illuminates if the PCM detects the above malfunction condition in two consecutive drive cycles or in one drive cycle while the DTC for the same malfunction has been stored in the PCM. • PENDING CODE is available if the PCM detects the above malfunction condition during the first drive cycle. • FREEZE FRAME DATA is available. • DTCs are stored in PCM memory.
POSSIBLE CAUSE | • Brake switch malfunction • Poor connection of the brake switch connector or the PCM connector • Short to the power supply between brake switch terminal D and PCM connector terminal 1K • Open circuit between brake switch terminal D and PCM connector terminal 1K • Open circuit between the battery positive terminal and brake switch terminal B • PCM malfunction

Diagnostic procedure

STEP | INSPECTION | ACTION
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1 | VERIFY FREEZE FRAME DATA AND DIAGNOSTIC MONITORING TEST RESULTS HAS BEEN RECORDED • Has FREEZE FRAME DATA been recorded? | Yes | Go to the next step.
No | Record the FREEZE FRAME DATA on the repair order, then go to the next step.
2 | VERIFY RELATED REPAIR INFORMATION AVAILABILITY • Verify related Service Information availability. • Is any related Service Information available? | Yes | Perform repair or diagnosis according to the available Service information. If the vehicle is not repaired, go to the next step.
No | Go to the next step.
3 | CLASSIFY HIGH INPUT OR LOW INPUT • Connect the WDS or equivalent to the DLC-2. • Access the BOO PID. • Verify the BOO PID during brake pedal operation. • Is the BOO PID always off? | Yes | Go to the next step.
No | Go to Step 10.
4 | INSPECT BRAKE SWITCH CONNECTOR FOR POOR CONNECTION • Turn the ignition switch to off. • Disconnect the brake switch connector. • Inspect for poor connection (such as damaged pulled-out terminals, corrosion). • Is there any malfunction? | Yes | Repair or replace the terminal, then go to Step 14.
No | Go to the next step.
5 | CLASSIFY BRAKE SWITCH OR CIRCUIT • Connect the WDS or equivalent to the DLC-2. • Access the BOO PID. • Connect a jumper wire between brake switch terminal B and D (harness-side). • Is the BOO PID on? | Yes | Go to the next step.
No | Go to Step 7.
6 | INSPECT BRAKE SWITCH • Perform the brake switch inspection. (See BRAKE SWITCH INSPECTION.) • Is the brake switch normal? | Yes | Go to Step 14.
No | Replace the brake switch, then go to Step 14.
7 | INSPECT BRAKE SWITCH POWER CIRCUIT FOR OPEN CIRCUIT • Measure the voltage between brake switch connector terminal B (harness-side) and body ground. • Is the voltage B+? | Yes | Go to the next step.
No | Repair or replace the brake switch power circuit for an open circuit, then go to Step 14.
8 | INSPECT PCM CONNECTOR FOR POOR CONNECTION • Turn the ignition switch to off. • Disconnect the PCM connector. • Inspect for poor connection (such as damaged/pulled-out pins, corrosion). • Is there any malfunction? | Yes | Repair or replace the terminal, then go to Step 14.
No | Go to the next step.
9 | INSPECT BRAKE SWITCH SIGNAL CIRCUIT FOR OPEN CIRCUIT • Inspect for continuity between brake switch terminal D (harness-side) and PCM terminal 1K (harness-side). • Is there continuity? | Yes | Repair or replace the wiring harness for an open circuit, then go to Step 14.
No | Go to Step 14.
10 | INSPECT BRAKE SWITCH CONNECTOR FOR POOR CONNECTION • Turn the ignition switch to off. • Disconnect brake switch connector. • Inspect for poor connection (such as damaged/pulled-out pins, corrosion). • Is there malfunction? | Yes | Repair or replace the terminal, then go to Step 14.
No | Go to the next step.
11 | CLASSIFY BRAKE SWITCH OR CIRCUIT • Connect the WDS or equivalent to the DLC-2. • Access the BOO PID. • Verify that the BOO PID changes from on to off when the brake switch connector is disconnected. • Does BOO PID change from on to off? | Yes | Go to the next step.
No | Go to Step 13.
12 | INSPECT BRAKE SWITCH • Perform the brake switch inspection. (See BRAKE SWITCH INSPECTION.) • Is the brake switch normal? | Yes | Go to Step 14.
No | Replace the brake switch, then go to Step 14.
13 | INSPECT BRAKE SWITCH SIGNAL CIRCUIT FOR SHORT TO POWER SUPPLY • Measure the voltage between brake switch connector terminal D (harness-side) and body ground. • Is the voltage B+? | Yes | Repair or replace the wiring harness for a short to power supply, then go to Step 14.
No | Go to the next step.
14 | VERIFY TROUBLESHOOTING OF DTC P0703 COMPLETED • Make sure to reconnect all disconnected connectors. • Clear the DTC from the memory using the WDS or equivalent. • Drive vehicle at 30 km/h {18.6 mph} or more. • Depress and release brake pedal more than 8 times while driving the vehicle. • Is the PENDING CODE for this DTC present? | Yes | Replace the PCM, then go to the next step. (See PCM REMOVAL/INSTALLATION [L3 Turbo].)
No | Go to the next step.
15 | VERIFY AFTER REPAIR PROCEDURE • Perform the "After Repair Procedure". (See AFTER REPAIR PROCEDURE [L3 Turbo].) • Are any DTCs present? | Yes | Go to the applicable DTC inspection. (See DTC TABLE [L3 Turbo].)
No | Troubleshooting completed.