Powertrain Management

DTC P0504

DTC Detecting Condition and Trouble Area






Wiring Diagram










DTC Confirmation Procedure

WARNING:

If you do not select a suitable route and take proper precautions when performing a road test, an accident can occur.

- Select a level road with no traffic to minimize the risk of accident.
- Perform the test extremely carefully.
- Perform the road test using 2 persons, a driver and an assistant.

1) Turn ignition switch to ON position.
2) Turn ON cruise control switch.
3) Keep brake pedal at depressed position for 5 sec.

DTC Troubleshooting

1.
Was "Engine and Emission Control System Check" performed?
YES -
Go to Step 2.
NO -
Go to Engine and Emission Control System Check Engine and Emission Control System Check.

2. Brake switch check

Check brake switch. Testing and Inspection

Is it in good condition?
YES -
Go to Step 3.
NO -
Replace brake switch.

3. Brake switch power circuit check

Disconnect brake switch connector with ignition switch turned OFF.
Check for proper connection to brake switch connector.
If connections are OK, check that circuit voltage between "Power supply circuit of brake pedal switch" or "Power supply circuit of brake light switch" and vehicle body ground is battery voltage with ignition switch turned ON.

Are they in good condition?
YES -
Go to Step 4.
NO -
Check related fuse and repair defective circuit.

4. Brake switch signal circuit check

Disconnect ECM with ignition switch turned OFF.
Check for proper connection of each switch circuit terminal to ECM connector.
If connections are OK, check that brake switch circuit is as follows.
- Wiring harness resistance of each "Signal circuit of brake pedal switch" and "Signal circuit of brake light switch" is less than 1 ohms.
- Insulation resistance of wire harness is infinity between "Signal circuit of brake pedal switch" or "Drive circuit of brake light switch" and vehicle body ground.
- Insulation resistance of wire harness is infinity between "Signal circuit of brake pedal switch" and "Drive circuit of brake light switch".
- Circuit voltage between "Drive circuit of brake pedal switch" or "Signal circuit of brake light switch" and vehicle body ground is 0 V with ignition switch turned ON.

Are they in good condition?
YES -
Substitute a known-good ECM and recheck.
NO -
Repair or replace defective wire.