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DTC P0122: Throttle Position (TP) Sensor Input Low: Testing

NOTE: Record freeze frame data. Check for service bulletins and on-line information.
  1. Connect scan tool to DLC-2. Turn ignition on. Check TP V PID while slowly depressing accelerator pedal. If PID is less than .16 volt, go to next step. If PID is .16 volt or more, problem is intermittent. See TROUBLE SHOOTING - NO CODES article.
  2. Disconnect TP sensor connector. Connect a fused jumper wire between harness connector terminals No. 1 (Yellow wire) and No. 2 (White wire). See WIRING DIAGRAMS article. Using scan tool, check ECT V PID. If PID is more than 4.9 volts, go to next step. If PID is less than 4.9 volts, go to step  4 .
  3. Check continuity between TP sensor terminals No. 1 and No. 2. If continuity is not present, replace TP sensor and go to step  10 . If continuity is present, repair poor contact at TP sensor harness connector terminal No. 1 and go to step  10 .
    NOTE: If DTC P0107 and P0452 are also present, go to REFERENCE VOLTAGE test in SYSTEM & COMPONENT TESTING - MIATA, MILLENIA, MPV, PROTEGE & 626 article.
  4. Turn ignition on. Check voltage in Yellow wire between ground and TP sensor harness connector terminal No. 1. If voltage is not 4.5-5.5 volts, go to next step. If voltage is 4.5-5.5 volts, go to step  6 .
  5. Disconnect 12-pin connector X-09, located at top right side of engine. Check voltage between male harness connector terminal "C" (Yellow wire) and ground. If voltage is 4.5-5.5 volts, repair open in Yellow wire between female connector X-09 terminal "C" and TP sensor harness connector terminal No. 1. Go to step  10 . If voltage is not 4.5-5.5 volts, repair open Pink/Blue wire between PCM terminal No. 90 and male connector X-09 terminal "C". Go to step  10 .
  6. Check continuity of White wire between female harness connector X-09 terminal "H" and TP sensor harness connector terminal No. 2. If continuity is present, go to next step. If continuity is not present, repair open in White wire between TP harness connector terminal No. 2 and female harness connector X-09 terminal "H". Go to step  10 .
  7. Check continuity of White wire between ground and female harness connector X-09 terminal "H". See WIRING DIAGRAMS article. If continuity is not present, go to next step. If continuity is present, repair short in White wire between harness connector X-09 terminal "H" and TP sensor harness connector terminal No. 2. Go to step  10 .
  8. Disconnect PCM harness connector. PCM is mounted to passenger floor, behind glove box. Connect breakout box to harness connector. See Figure . Leave PCM disconnected. Check continuity of Brown/Yellow wire between male harness connector X-09 terminal "H" and breakout box terminal No. 89. If continuity is present, go to next step. If continuity is not present, repair open in Brown/Yellow wire between male harness connector X-09 terminal "H" and PCM harness connector terminal No. 89. Go to step  10 .
  9. Check continuity between breakout box terminal No. 89 and ground. If continuity is present, repair short in Brown/Yellow wire between male harness connector X-09 terminal "H" and PCM harness connector terminal No. 89. Go to next step. If continuity is not present, repair short between TP sensor ground circuit (Brown wire) and TP sensor signal circuit (White wire from TP sensor, Brown/Yellow wire from PCM). Go to next step.
  10. Reconnect all components. Turn ignition on. Using scan tool, clear DTC. Start engine. Ensure TP V PID is .1-4.9 volts. Recheck DTCs. If DTC P0122 is present, replace PCM and go to next step. If DTC P0122 is not present, go to next step.
  11. Perform after repair procedure. See AFTER REPAIR PROCEDURE  . If DTC is not present, testing is complete. If any DTC is present, go to appropriate test for diagnosis and repair.
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