C05D7

Code

Generic C — Chassis

Brake Transmission Shift Interlock (BTSI) Control Circuit

Brand: Generic

Type: C — Chassis

Views: UK: 26 EN: 59 RU: 28

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Page language: EN

Causes

Open or short in BTSI wiring or connector
Corroded or loose connector pins at BTSI, fuse box, or control module
Faulty BTSI solenoid/actuator or internal mechanical binding
Failed brake pedal position/switch (brake light switch) or misadjusted pedal
Blown fuse or faulty relay supplying BTSI circuit
Poor ground(s) in BTSI/control module circuits

Symptoms

Cannot shift out of Park (shift lever locked)
Intermittent or inconsistent release of shift lock when brake applied
Shift interlock warning or indicator lamp (if equipped)
Brake lights may be inoperative if brake switch is related
Clicking from BTSI area when attempting to shift
Malfunction Indicator Light (MIL) or related warning codes may be present

What to check

Retrieve all stored codes and freeze-frame data with a scan tool; note related/communication codes
Visual inspection of BTSI connector, wiring harness, grounds and for water/corrosion
Check relevant fuses and relays for continuity and proper operation
Verify brake pedal switch function (voltage/resistance and brake light operation)
Backprobe BTSI connector while operating brake pedal and attempting to shift to measure voltages
Measure coil resistance of BTSI solenoid if accessible (compare to spec)

Signal parameters

BTSI command voltage: typically near battery voltage (~11–14 V) when coil should be energized; 0 V when not energized (exact values vary by vehicle)
BTSI coil resistance: typically low ohms (example 5–50 Ω) — consult vehicle spec; an open or short is a fault
Brake switch signal: open circuit at rest, closes to battery voltage when pedal depressed (or vice versa on some systems)
Control module logic: digital command (on/off) from BCM/TCM; CAN messages present when system powered
Ground: near 0 V reference; poor ground may show elevated resistance/voltage under load

Diagnostic algorithm

Connect a professional scan tool. Record C05D7 and any other active/history codes; view freeze-frame and live data for BTSI, brake switch status, and related inputs.
Inspect connectors, wiring, and grounds for damage, corrosion, or loose pins at BTSI, fuse/relay box and control module. Repair any physical damage.
Check fuses/relays in the BTSI feed circuit for continuity and correct operation; replace if faulty.
Verify brake light switch operation: confirm brake lights illuminate when pedal depressed and confirm the switch changes state at the expected pedal travel. Replace or adjust switch if out of spec.
Backprobe BTSI connector while commanding the interlock (apply brake/shifter). Measure supply voltage to the BTSI and the command/ground return. Compare to expected battery voltage and 0 V return.
Measure BTSI coil resistance with harness disconnected. Replace BTSI actuator if coil is open, shorted, or outside specification, or if actuator fails to move when properly powered.
If wiring/actuator checks good but fault persists, check continuity between BTSI connector and controlling module pins. Repair any opens/shorts.
Check for related communication errors (U-codes). If module communication faults exist, diagnose network issues before replacing BTSI or BCM.
After repairs, clear codes and test-drive/operate vehicle through multiple cycles to confirm repair and that C05D7 does not return.
If fault remains after wiring and component checks, suspect control module internal fault or software; consult manufacturer service information for module reprogramming or replacement guidance.