DTC 38

CIRCUIT OPERATION
The ON signal when the brake pedal is pressed or the OFF signal when the brake pedal is released is input to the ABS-ECU (terminal 14).

ABS DTC SET CONDITION
Output is provided in the following cases:
- Stoplight switch is not operating properly and remains in ON state for more than 15 minutes.
- Stoplight switch system harness is damaged and no signal is input to ABS-ECU.

TROUBLESHOOTING HINTS
The most likely causes for DTC is to set are:
- Malfunction of the stoplight switch
- Damaged wiring harness and connector
- Malfunction of the hydraulic unit (Integrated with ABS-ECU)

DIAGNOSIS
Required Special Tool: MB991223: Harness Set

STEP 1. Check the stoplight operation.
If the stoplight does not light, go to Step 2.
If the stoplight correctly lights and goes out, go to Step 3.

STEP 2. Check the stoplight switch installation condition.
If the stoplight switch is not installed properly, repair it. Then go to Step 7.
If the stoplight switch is installed properly, go to Step 4.





STEP 3. Check the stoplight switch circuit at ABS-ECU connector Amp.
1. Disconnect connector A-02 and measure at the harness side.
2. Turn the stoplight switch ON.
3. Measure the voltage between terminal 14 and ground. Voltage should be approximately 12 volts (battery positive voltage)
If not approximately 12 volts, go to Step 5.
If approximately 12 volts, replace the hydraulic unit (integrated with ABS-ECU). Then go to Step 7.

STEP 4. Check the stoplight switch continuity.
1. Remove the stoplight switch.





2. Connect an ohmmeter to the stoplight switch terminals 1 and 2, and check whether there is continuity when the plunger of the stoplight switch is pushed in and when it is released.





3. The stoplight switch is in good condition if there is no continuity when the plunger is pushed in to a depth of within 4 mm (0.2 inch) from the outer case edge surface, and if there is continuity when it is released.
If the stoplight switch is damaged, replace it. Then go to Step 7.
If the stoplight switch is not damaged, go to Step 6.

STEP 5. Check the harness wire between ABS-ECU connector A-02 and intermediate connector C-89.








If any harness wire between ABS-ECU connector A-02 and intermediate connector C-89 is damaged, repair it. Then go to Step 7.





NOTE: After inspecting intermediate connector C-13, inspect the wire. If intermediate connector C-13 is damaged, repair or replace it.

Refer to Harness Connector Inspection. Component Tests and General Diagnostics If the connector has been repaired or replaced, go to Step 7.

STEP 6. Check the harness wire between fusible link number 2 and stoplight switch connector C-03.





If any harness wire between fusible link number 2 and stoplight switch connector C-03 is damaged, repair it. Then go to Step 7.











NOTE: After inspecting intermediate connector C-89, C-107, or C-110, inspect the wire. If intermediate connector C-89, C-107 or C-110 is damaged, repair or replace it. Refer to Harness Connector Inspection. Component Tests and General Diagnostics If the connector has been repaired or replaced, go to Step 7.

STEP 7. Check the diagnostic trouble codes.
Confirm that diagnostic trouble code 38 does not reset.