DTC C0075-Additional Diagnostic Procedures (06-67-18)

Publication date: 2018-10-19
Reference number: 06-67-18

DTC C0075-ADDITIONAL DIAGNOSTIC PROCEDURES

TECHNICAL SERVICE BULLETIN

Reference Number(s): 06-67-18, Date of Issue: October 19, 2018

SUBARU:

2013-2014 Legacy and Outback with EyeSight; 2015-2016 Impreza with EyeSight; 2015-2017 Crosstrek with EyeSight

APPLICABILITY

2013-2014MY Legacy and Outback with EyeSight

2015-2016MY Impreza with EyeSight

2015-2017MY Crosstrek with EyeSight

INTRODUCTION

This Service Information Bulletin provides additional steps to follow when diagnosing a DTC C0075: WHEEL CYLINDER PRESSURE SENSOR OUTPUT on the EyeSight equipped models listed above. The information in this bulletin is applicable when DTC C0075 is accompanied by detail codes 5090 and/or 5101. The additional diagnostics are intended to reduce unnecessary replacement of the Hydraulic Unit (H/U) Assembly.

SERVICE PROCEDURE/INFORMATION

REMINDER: Customer satisfaction and retention starts with performing quality repairs. Always refer to the applicable Service Manual and review the full requirements of the repairs being performed. The Service Manual procedures contain information critical to performing an effective repair the first time and every time. This includes but is not limited to: important SAFETY precautions, proper inspection criteria, necessary special tools, required processes and related onetime-use parts needed for a complete and lasting repair.

As referenced in the Introduction above, current Service Manual diagnostics indicate replacement of the brake system H/U as the repair for this DTC but, the root cause of C0075 and detail codes 5090 and/or 5101 may be related to a difference between the right and left wheel cylinder pressure sensor signal values. This difference causes the pressure sensor component(s) of the H/U to be judged as abnormal. Since the sensors are not serviceable, replacement of the H/U is required.

For this reason, these other potential causes must be investigated and ruled out in the order listed below BEFORE replacing the H/U:

Brake hydraulic system contaminated with air
Stop lamp switch "ON" point out of adjustment
Deterioration (wear and/or rusting) of brake components.

Step 1: Bleeding the brake system:

Bleed the brake system thoroughly following the procedure in the applicable Service Manual.
IMPORTANT: It is critical to follow the brake bleeding sequence outlined in the applicable Service Manual when. If performed in the wrong order, air will remain in the system.
Perform the "ABS Sequence Control" procedure once using the SSM.
Bleed the brake system thoroughly following the procedure in the applicable Service Manual.
Perform the "VDC Sequence Control" procedure once using the SSM.
Bleed the brake system thoroughly following the procedure in the applicable Service Manual.
Repeat the above steps 2 to 5 at least three times until all the air has been purged.

Step 2: Stop lamp switch adjustment:

Adjust the stop light switch following the procedures outlined in the applicable TSB:

For the notched, "Twist-Lock" -type stop lamp switch, see TSB 07-128-18R.
For the threaded "Lock Nut" -type stop lamp switch, see TSB 07-131-18R .

Step 3: Individual brake system component inspection:

IMPORTANT: If the brake rotors and pads are found to be in serviceable condition and no concerns are observed with them, the next step would be to inspect the brake hoses. If pressure variation can be observed using SM4, the possibility exists of internal damage to the hose(s). This is particularly possible if there is a history of prior front brake servicing and there are any indications on the hose showing possible clamp usage or the caliper(s) being supported by the hose during past servicing.

When the rotor is rusted as shown in the photos below, replace it with a new rotor and brake pad set even if the rotor thickness has not reached minimum thickness.
When the pad shims are rusted or deformed as shown below, replace with new shims.

IMPORTANT REMINDERS:

SOA strongly discourages the printing and/or local storage of service information as previously released information and electronic publications may be updated at any time.
Always check for any open recalls or campaigns anytime a vehicle is in for servicing.
Always refer to STIS for the latest service information before performing any repairs.