C1201 fault code: what it means

C1201: Engine control system malfunction: the ABS/VSC computer has switched VSC and TRAC off because the engine ECU has a fault. Fix the engine code(s) first.

Chassis (brakes, steering, suspension) · Keep an eye on

Usual causes, most likely first

another engine fault code stored (check engine light on)
loose fuel cap / EVAP fault triggering the engine light
ECM fault (rare)

C1201 by make

Lexus

Engine control system malfunction: the ABS/VSC computer has switched VSC and TRAC off because the engine ECU has a fault. Fix the engine code(s) first.

Usual causes: another engine fault code stored (check engine light on); loose fuel cap / EVAP fault triggering the engine light; ECM fault (rare)

Toyota

Engine control system malfunction: the ABS/VSC computer has switched VSC and TRAC off because the engine ECU has a fault. Fix the engine code(s) first.

Usual causes: another engine fault code stored (check engine light on); loose fuel cap / EVAP fault triggering the engine light; ECM fault (rare)

What the repair usually costs

Air-fuel ratio / front O2 sensor replace (upstream)NZ$270–NZ$750 · A$260–A$730
O2 sensor replace (downstream / after cat)NZ$180–NZ$480 · A$180–A$460
MAF (mass air flow) sensor replaceNZ$170–NZ$660 · A$160–A$600
Diagnostic scan, fault code read and report (warning light on)NZ$70–NZ$140 · A$80–A$150

Not sure what C1201 means on your car? Ask Credov.

Before you clear it

Write the code down or photograph the scanner first. A code that comes straight back after clearing points to a fault that is still there. A car whose codes were cleared just before you arrived may be hiding one: the scanner's readiness monitors show "not ready" for a while after codes are cleared.

Researched by Credov from manufacturer and workshop sources. A fault code points to where a fault may be; a workshop confirms it with a diagnosis. Browse all fault codes.