DTC P1240: Throttle Motor Short Circuit
- Disconnect throttle body harness connector. Connect SST 86 11 857 test light (see Figure) or equivalent to throttle body harness connector terminals No. 5 (Red/Blue wire) and 10 (Orange/Green wire). See Figure. 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 operates as specified, replace throttle body and go to step 3. See THROTTLE BODY
under FUEL SYSTEM in REMOVAL, OVERHAUL & INSTALLATION article. If test light does not operate as specified, go to next step.NOTE: Limp-home mechanism must be reset after all DTCs have been erased, otherwise limp-home solenoid will be activated.
- Check for faulty circuit between throttle body harness connector terminal No. 5 and ECM harness connector terminal No. 48 (Red/Blue wire). Check for faulty circuit between throttle body harness connector terminal No. 10 and ECM harness connector terminal No. 24 (Orange/Green wire). See Figure for ECM location. See Figure for ECM terminal identification. See WIRING DIAGRAMS article. Repair as necessary and go to next step.
- 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 under TESTING & REPAIR PROCEDURE. Use scan tool to clear all system DTCs. Drive vehicle for 5 minutes under varying loads and engine RPM. Recheck for any stored DTCs. If DTC P1240 is present, substitute known good ECM and retest system. See ENGINE CONTROL MODULE (ECM) under COMPUTERIZED ENGINE CONTROLS in REMOVAL, OVERHAUL & INSTALLATION article.