Home ReviewsRefund
Home/Saab/9-3/Saab 9-3 I (1998-2003)/Repair manual/Testing & Diagnostics/DTC P1251-P1253: THROTTLE MOTOR FULL PULSE-WIDTH MODULATION…
Contents Wiring diagrams Section: Testing & Diagnostics All sections

DTC P1251-P1253: THROTTLE MOTOR FULL PULSE-WIDTH MODULATION MALFUNCTION Saab 9-3 I

Testing & Diagnostics ~488 words

Note. DTC P1251 may set if limp-home mechanism was not reset after servicing throttle body. See RESETTING LIMP-HOME SOLENOID under TESTING & REPAIR PROCEDURE.

Note. To diagnose DTC P1252, start at step 2 .

  1. Turn ignition off. Wait 10 seconds, then open and close throttle by hand. (Схема №12) Ensure that throttle is not obstructed and that throttle spring returns throttle valve completely until contacting stop screw. If throttle valve operation is as specified, go to next step. If throttle valve operation is not as specified, repair or replace throttle body as necessary. See «THROTTLE BODY»(ref-2997-S11301002242000041700000) under FUEL SYSTEM in REMOVAL, OVERHAUL & INSTALLATION article. Go to step 3.
  2. Disconnect throttle body harness connector. Connect SST 86 11 857 test light (Схема №5) or equivalent to throttle body harness connector terminals No. 5 (Red/Blue wire) and 10 (Orange/Green wire). (Схема №15) Connect TECH 2 scan tool to Data Link Connector (DLC). Turn ignition on. Select ACTIVATE: THROTTLE MOTOR PWM TEST. The test light should alternate between green and red. If test light does not operate as specified, check for faulty circuit between throttle body harness connector terminal No. 5 and ECM harness connector terminal No. 48 (Red/Blue wire). (Схема №1)for ECM location. (Схема №7)for ECM terminal identification. Check for faulty circuit between throttle body harness connector terminal No. 10 and ECM harness connector terminal No. 24 (Orange/Green wire). See appropriate wiring diagram in «WIRING DIAGRAMS»(ref-3491) article. Repair as necessary. If test light does operate as specified, replace throttle body. See «THROTTLE BODY»(ref-2997-S11301002242000041700000) under FUEL SYSTEM in REMOVAL, OVERHAUL & INSTALLATION article. Go to next step. NOTE: Limp-home mechanism must be reset after all DTCs have been erased, otherwise limp-home solenoid will be activated.
  3. If diagnosing DTC P1251 or P1252 and you were sent here from DTC P0507, go to step 7 of DTC P0507 diagnostic procedure. Otherwise, turn ignition on. Use scan tool to clear Trionic T-7 Engine Management System DTCs. Turn ignition off. Wait 10 seconds. Reset limp-home mechanism. See «RESETTING LIMP-HOME SOLENOID»(ref-2998-S16464387302000041700000) under TESTING & REPAIR PROCEDURE. Disconnect EVAP canister purge valve harness connector. Connect test light between purge valve harness connector terminals No. 1 and 2. Start engine and allow it to idle until coolant temperature exceeds 140°F (60°C). Use scan tool to select READ VALUE: PURGE ADAPTATION. If value displayed is -15 percent to +15 percent, go to next step. If value displayed is not as specified, problem is still present.
  4. Turn ignition off and remove test light. Reconnect purge valve harness connector. Test drive vehicle between 37-62 MPH with constant throttle applied. Select READ VALUE: MULTIPLICATIVE ADAPTATION. Wait until reading changes, then change speed or stop if desired. Wait until scan tool reading stabilizes. If scan tool value is between -15 percent and +15 percent, system is operating normally. Clear all system DTCs. If scan tool value is not as specified, problem is still present.

More articles — Engine Controls - Self-Diagnostics - Trionic T7 Fuel Control System