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Home >> Suzuki >> 2002 >> XL-7 Plus >> Repair and Diagnosis >> External Pages >> Different car >> Section 6 (Engine Controls - Self-Diagnostics) >> Diagnostic Tests >> DTC P1220: Throttle Position Sensor 2 - Circuit Fault >> Diagnostic Procedure
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Diagnostic Procedure

WARNING: This page is about a different car, the 2002 Isuzu Trooper. However, it is still accessible from the selected car via links, so may be relevant.
  1. Perform ON-BOARD DIAGNOSTIC II SYSTEM CHECK  under SELF-DIAGNOSTIC SYSTEM. After performing OBD-II system check, go to next step.
  2. Perform ELECTRIC THROTTLE CONTROL SYSTEM CHECK  under SELF-DIAGNOSTIC SYSTEM. After performing electronic throttle control system check, go to next step.
  3. Turn ignition off. Disconnect Crankshaft Position (CKP) sensor 3-pin harness connector. CKP sensor is located on lower right side of engine. Turn ignition on. Using DVOM, measure voltage between CKP harness connector terminals No. 2 (Green wire) and No. 3 (Yellow wire). Voltage reading should be about 5 volts. If voltage is as specified, go to step  5. If voltage is not as specified, go to next step.
  4. Check for open or short circuit in Yellow wire between PCM and CKP sensor. See WIRING DIAGRAMS article. If problem is found, repair as necessary. After repair is complete, see VERIFYING VEHICLE REPAIR  under SELF-DIAGNOSTIC SYSTEM. If no problem is found, go to step  16.
  5. Replace CKP sensor. See REMOVAL, OVERHAUL & INSTALLATION article. After repair is complete, see VERIFYING VEHICLE REPAIR  under SELF-DIAGNOSTIC SYSTEM.
  6. Turn ignition on. Using scan tool, observe Accelerator Position Sensor 2 (APS2) parameter. At closed throttle APS2 parameter should be 83-91 percent, at wide open throttle APS2 parameter should be 9-17 percent. If APS2 parameter is as specified, go to next step. If APS2 parameter is not as specified, go to step  10.
  7. Disconnect APS2 10-pin harness connector. APS2 is located on accelerator pedal. Connect jumper wire between APS2 harness connector terminals No. 8 (Green wire) and No. 9 (Yellow wire). Using scan tool, observe APS2 voltage parameter. If voltage parameter is about 5 volts, go to step  9. If voltage parameter is not as specified, go to next step.
  8. Check for open or short circuit in Yellow wire (APS2 signal circuit) between PCM and APS2. See WIRING DIAGRAMS article. Check for short to each other in APS2 signal and ground circuits. If problem is found, repair as necessary. After repair is complete, see VERIFYING VEHICLE REPAIR  under SELF-DIAGNOSTIC SYSTEM. If no problem is found, go to step  16.
  9. Replace APS2. See REMOVAL, OVERHAUL & INSTALLATION article. After repair is complete, see VERIFYING VEHICLE REPAIR  under SELF-DIAGNOSTIC SYSTEM.
  10. Ensure engine is at operating temperature, minimum 176°F (80°C). Turn ignition on. On scan tool, observe TPS2 angle parameter. As accelerator pedal is pressed to floor, TPS2 angle should increase smoothly and evenly from 88-94 percent at closed throttle to 19-23 percent at wide open throttle. If TPS2 angle parameter performs as specified, go to next step. If TPS2 angle parameter does not perform as specified, go to step  12.
  11. Using scan tool, retrieve DTCs. If DTC P1120 was set, go to step  16. If DTC P1120 was not set, check for intermittent problem. See DIAGNOSTIC AIDS .
  12. Turn ignition off. Disconnect TPS 8-pin harness connector. TPS is located on throttle body, at front of intake manifold. Using DVOM, measure voltage between TPS harness connector terminals No. 4 (Green/White wire) and No. 8 (Red/White wire). See Figure. Voltage reading should be about 5 volts. If voltage is as specified, go to next step. If voltage is not as specified, go to step  16.
  13. Check TPS2 signal circuit for a short to voltage. See WIRING DIAGRAMS article. Check TPS2 sensor ground circuit for high resistance or faulty connection between PCM harness connector and TPS sensor harness connector. If problem is found, repair as necessary. After repair is complete, see VERIFYING VEHICLE REPAIR  under SELF-DIAGNOSTIC SYSTEM. If no problem is found, go to next step.
  14. Check TPS2 signal circuit or 5-volt reference circuit for faulty connection or high resistance between PCM harness connector and TPS sensor harness connector. If problem is found, repair as necessary. After repair is complete, see VERIFYING VEHICLE REPAIR  under SELF-DIAGNOSTIC SYSTEM. If no problem is found, go to next step.
  15. Replace TPS. See REMOVAL, OVERHAUL & INSTALLATION article. After repair is complete, see VERIFYING VEHICLE REPAIR  under SELF-DIAGNOSTIC SYSTEM.
  16. Replace and reprogram PCM. See POWERTRAIN CONTROL MODULE REPLACEMENT  under POWERTRAIN CONTROL MODULE. Use scan tool to clear DTC and verify repair.
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