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.
- Remove glove box and ECM, leaving ECM connectors connected. ECM is located behind glove box. See Figure. Backprobing, measure voltage between ECM 34-pin connector E4 terminal No. 33 (+) (Green/Red wire) and ECM 32-pin connector E6 terminal No. 1 (-) (Brown wire). With shift indicator in P or N position and ignition switch in START position, voltage should be 9-14 volts. With ignition in ON position, voltage should be 0-3 volts. See Figure. If voltage is as specified, replace ECM. If voltage is not as specified, go to next step.
- Remove the fuel pump relay from the engine room relay box. See Fig 1. Inspect the fuel pump relay. See FUEL PUMP RELAY under MODULES, MOTORS, RELAYS & SOLENOIDS in SYSTEM & COMPONENT TESTING - V6 & V8 article. If relay is Ok, go to next step. If relay is bad, replace relay.
- Disconnect ECM 34-pin connector E4. Check continuity between fuel pump relay socket terminal No. 1 and ECM 34-pin connector terminal No. 33 (Green/Red wire). Continuity should exist. Then, check continuity between fuel pump relay socket terminal No. 1 and ground. Continuity should not exist. If continuity is as specified, replace ECM. If continuity is not as specified, repair or replace harness wires or connectors as necessary.