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Home >> Toyota >> 2001 >> Sienna CE >> Repair and Diagnosis >> External Pages >> Different car >> Section 125 (Engine Control System Self Diagnostics (2UZ-FE)) >> Diagnostic Tests >> DTC P0100, DTC P0102 &/Or DTC P0103 >> Diagnosis & Repair

Diagnosis & Repair

WARNING: This page is about a different car, the 2003 Toyota 4Runner. However, it is still accessible from the selected car via links, so may be relevant.
  1. Connect Toyota hand-held tester or scan tool to Data Link Connector (DLC3) at driver's side of instrument panel. See Figure. Turn ignition on and then turn hand-held tester or scan tool on. Start engine and allow engine to idle. Using hand-held tester or scan tool, monitor MAF meter air flow rate. If MAF meter air flow rate is 0.0 gm/sec., go to next step. If MAF meter air flow rate is 271 gm/sec. or more, with engine idling and at normal operating temperature, go to step  6.
  2. Turn ignition off. Disconnect Black, 5-pin harness connector from MAF meter. MAF meter is bolted to air intake hose, near air cleaner assembly. Turn ignition on. Using voltmeter, check voltage between body ground and MAF meter harness connector terminal No. 3 (Blue/White wire). See Fig 1. If voltage is 9-14 volts, go to next step. If voltage is not 9-14 volts, check EFI No. 2 fuse located in engine room fuse/relay box. Also, check for open or short in Blue/White wire between MAF meter and EFI main relay located in engine room fuse/relay box. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article. If problem is found, repair as necessary. If problem is not found, go to next step.
  3. Turn ignition off. Reinstall electrical connector at MAF meter. Remove glove box for access to ECM with electrical connectors still installed on ECM. See Figure. Start engine. Measure voltage at ECM 34-pin connector E4 with negative probe on terminal No. 29 (Black/White wire) and positive probe on terminal No. 30 (White/Red wire). See Figure. Voltage should be 0.5-3.0 volts at idle. If voltage is as specified, go to next step. If voltage is not as specified, replace ECM.
  4. Disconnect ECM 34-pin connector E4 and MAF sensor 5-pin connector. Check continuity of White/Red wire between ECM 34-pin connector E4 terminal E30 and MAF sensor harness connector terminal No. 5. Also, check continuity of Black/White wire between ECM 34-pin harness connector E4 terminal E29 and MAF sensor harness connector terminal No. 4. Continuity should exist. Then, check continuity between ground and ECM 34-pin connector E4 terminal E30. Continuity should not exist. If continuity is as specified, go to next step. If continuity is not as specified, repair wiring harness or connectors as necessary.
  5. Check EFI fuse No. 2 located in engine room fuse/relay box. Replace as necessary. Disconnect EFI relay from engine room fuse/relay box. Check continuity between EFI main relay socket terminal No. 3 and MAF 5-pin connector terminal No. 3 (Blue/White wire). Continuity should exist. Then, check continuity between ground and EFI main relay socket terminal No. 3. Continuity should not exist. If continuity is as specified, check ECM power circuits, and repair as necessary. If circuits are okay, go to next step. If continuity is not as specified, repair open or short circuit in wire or connector as necessary. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article.
  6. Turn ignition off. Remove glove box for access to ECM with electrical connectors still installed on ECM. See Figure. Check continuity between ground and ECM 34-pin connector E4 terminal No. 29 (Black/White wire). See Figure. If continuity exists, go to next step. If continuity does not exist, replace ECM.
  7. Disconnect ECM 34-pin connector E4 and MAF sensor 5-pin connector. Check continuity of White/Red wire between ECM harness connector E4 terminal No. E30 and MAF sensor harness connector terminal No. 5. Also, Check continuity of Black/White wire between ECM harness connector E4 terminal No. E29 and MAF sensor harness connector terminal No. 4. See Figure & Fig 1 . Continuity should exist. Then, check continuity between ground and ECM connector terminal No. 30. Continuity should not exist. If continuity is as specified, replace MAF sensor. See AIRFLOW METER under ENGINE SENSORS & SWITCHES in REMOVAL, OVERHAUL & INSTALLATION - V6 & V8 article. If continuity is not as specified, repair wiring harness and electrical connectors as necessary.
    Fig 1: Identifying MAF Sensor Circuit & Connectors
    G00228903Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
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