LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Saturn >> 2000 >> LS Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics >> Diagnostic Tests >> DTC P0201: Injector No. 1 Control Circuit >> Diagnostic Procedures
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Diagnostic Procedures

  1. Perform On-Board Diagnostic (OBD) system check. See ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK  under SELF-DIAGNOSTIC SYSTEM. After performing OBD system check, go to next step.
  2. Check if all injector DTCs are set. If not all 4 injector DTCs are set, go to next step. If all 4 injectors DTCs are set, repair ignition voltage to injectors. Check injector fuse in underhood fuse block.
  3. Operate engine for one minute. Using scan tool, monitor status of DTC P0201. If this DTC failed this ignition cycle, go to next step. If this DTC did not fail this ignition cycle, problem is intermittent. See DIAGNOSTIC AIDS .
  4. Turn ignition off. Disconnect fuel injector No. 1 harness connector. Connect Injector Test Light (J-34730-405) to injector harness connector. Start or crank engine. If injector test light is always off, go to next step. If injector test light pulses, check for terminal tightness at injector connector. Repair as necessary. If injector test light is always on, check for short in injector harness connector terminal "B" (Black wire) circuit. Repair as necessary. If circuit is okay, replace PCM.
  5. Turn ignition on, with engine off. Connect a test light between ground and fuel injector harness connector terminal "A" (Pink wire). If test light does not illuminate, go to next step. If test light illuminates, repair open in circuit. See WIRING DIAGRAMS article.
  6. Turn ignition off. Disconnect PCM harness connector J1. Turn ignition on. Using a DVOM, check voltage on fuel injector harness connector terminal "B" (Black wire). If voltage is present, repair short to voltage in circuit. If voltage is not present, check for open in circuit or terminal tightness. Repair as necessary. If circuit or terminals are okay, replace PCM.
scientia non olet · About LEMON Manuals