DTC P0121 - Throttle Position (TP) Sensor System Performance

NOTE: If DTCs P0121, P0122 and P0123 are set together, diagnose P0122 and P0123 first.

Disconnect negative battery cable. Unplug TP sensor harness connector. Using an ohmmeter, measure resistance between specified terminals of TP sensor. See TP SENSOR RESISTANCE table. See Fig 1 . Adjust TP sensor if idle switch resistance is not as specified. Replace TP sensor if specified resistance cannot be obtained. If TP sensor resistance is okay, replace PCM. Retest system.

Fig 1: Identifying TP Sensor Terminals

Courtesy of SUZUKI OF AMERICA CORP.

TP SENSOR RESISTANCE

Between Terminals

Ohms

A & B

⁽¹⁾ 10-500

A & B

⁽²⁾ Infinity

A & D

⁽³⁾ 3500-6500

A & C

⁽⁴⁾ 300-2000

A & C

⁽⁵⁾ 2000-6500

⁽¹⁾	When throttle lever-to-stop screw clearance is .020 in. (0.5mm).

⁽²⁾	When throttle lever-to-stop screw clearance is .031 in. (0.8mm).

⁽³⁾

Constant.

⁽⁴⁾	Throttle valve at idle position.

⁽⁵⁾	Throttle valve at fully open position.