DTC P0122: Throttle Position (TP) Circuit Low Input

NOTE: On Esteem 1.6L and Swift, if DTC P0107, P0122 and/or P0450 are set together, Check PCM harness connector C22 terminal No. 1 (Pink/Green wire on Esteem, or Light Green wire on Swift) for an open circuit.

Connect scan tool to Data Link Connector (DLC). Turn ignition on. Observe throttle valve opening percentage on scan tool. If display reads zero percent (Esteem 1.8L) or 2 percent or less (Esteem 1.6L and Swift), go to next step. If display reading is not zero percent (Esteem 1.8L) or greater than 2 percent (Esteem 1.6L and Swift), check for an intermittent problem. Go to INTERMITTENTS in TROUBLE SHOOTING - NO CODES article.
Turn ignition off. Disconnect TP sensor harness connector. Turn ignition on. Measure voltage between ground and Pink/Green (Esteem), Gray (Esteem, 1.8L only) or Light Green (Swift) wire at TP sensor harness connector. If voltage is 4-6 volts, go to next step. If voltage is not 4-6 volts, check for open circuit in Pink/Green, Gray or Light Green wires. If reading is not as specified, check wire for an open, short to ground, or short to Green/Red (Esteem) or Light Green/Black (Swift) wire. Repair as necessary. If wire is okay, go to next step.
On Esteem 1.8L, go to next step. On all other models, measure voltage between ground and Gray (Esteem) or Light Green/White (Swift) wire at TP sensor harness connector. Reading should be 4-6 volts. If reading is as specified, go to next step. If reading is not as specified, check wire for a short to ground and retest system. If wire is okay, replace PCM and retest system.
Measure resistance between specified TP sensor terminals. See Figure . See TP SENSOR RESISTANCE table. If resistance is not as specified, replace TP sensor. If resistance is as specified, replace PCM. Retest system.