DTC P0112-P0113: Intake Air Temperature (IAT) Sensor Circuit
- Disconnect IAT sensor harness connector. See Figure for IAT sensor and ECM locations. Connect SST 86 11 857 test light (see Figure) or equivalent between positive battery terminal and IAT sensor harness connector terminal No. 2 (Black wire). See Fig 1. If test light illuminates, go to next step. If test light does not illuminate, check for faulty circuit between IAT sensor harness connector terminal No. 2 and ground splice connector (Black wire) located about 2" from ECM harness connector cable tie. See appropriate wiring diagram in WIRING DIAGRAMS
article. Repair as necessary and go to step 4.
- Connect TECH 2 scan tool to Data Link Connector (DLC). Turn ignition on. Use scan tool to select READING: INTAKE AIR TEMPERATURE. Scan tool display should be -40°F (-40°C). If reading is as specified, go to next step. If reading is not as specified, check for faulty circuit between IAT sensor harness connector terminal No. 1 and ECM harness connector terminal No. 15 (White/Black wire). See Figure for ECM terminal identification. Repair as necessary and go to step 4.
- Connect a fused jumper wire between IAT sensor harness connector terminals No. 1 (White/Black wire) and 2 (Black wire). Scan tool display should now read 282°F (139°C). If reading is as specified, replace IAT sensor. If reading is not as specified, check for faulty circuit between IAT sensor harness connector terminal No. 1 and ECM harness connector terminal No. 15 (White/Black wire). Repair as necessary and go to next step.
- 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 P0112-P0113 is present, substitute known good ECM and retest system. See ENGINE CONTROL MODULE (ECM)
under COMPUTERIZED ENGINE CONTROLS in REMOVAL, OVERHAUL & INSTALLATION article.
Courtesy of SAAB-SCANIA OF AMERICA, INC.