Diagnosis & Repair
WARNING: This page is about a different car, the 2003 Lexus SC 430. However, it is still accessible from the selected car via links, so may be relevant.
- Connect scan tool. Disconnect EB1 3-pin connector located behind intake manifold. Using a fused jumper wire, connect terminal No. 2 (Black wire) on male part of connector to terminal No. 3 (White wire) on female part of connector. Connect another jumper wire between terminal No. 3 (Brown wire) on male part of connector to terminal No. 2 (Black wire) on female part of connector. See Fig 1. Turn ignition on. Turn scan tool on. Allow engine to reach its normal operating temperature. Snap throttle 3 times to 4000 RPM. Retrieve trouble codes. See RETRIEVING DIAGNOSTIC TROUBLE CODES under SELF-DIAGNOSTIC SYSTEM. If same DTC is repeated, go to next step. If DTC changed, go to step 3.
- Disconnect the EB1 connector. See Fig 2. Disconnect the E3 ECM connector. See Fig 3. Check the continuity between the wire harness side connectors. Continuity should be present between EB1 female connector terminal No. 3 and KNKL (E3-1), and between EB1 female connector terminal No. 2 and KNKR (E3-2). No continuity should be present between EB1 female connector terminal No. 3 or KNKL (E3-1 ) and E1 (E3-7), and between EB1 female connector terminal No. 2 or KNKR (E3-2) and E1 (E3-7). If not okay, check for short or open in wires between EB1 harness connector and ECM. Repair as necessary. If wiring harness is okay, replace ECM.
- If DTC P0325 has changed to P0330, check the knock sensor circuit on the left bank side. If DTC P0330 has changed to P0325, check the knock sensor circuit on the right bank side. Disconnect the EB1 connectors. See Fig 2. Disconnect the K1 knock sensor terminal No. 1 and K2 knock sensor terminal No. 2 connectors. See Fig 4. Check the continuity between the wire harness side connectors. Continuity should be present between EB1 female connector terminal No. 3 and K1-1, and between EB1 female connector terminal No. 2 and K2-1. Continuity should not be present between EB1 female connector terminal No. 3 or K1-1 and body ground, and between EB1 female connector terminal No. 2 or K2-1 and body ground. If okay, replace knock sensor. If not okay, repair or replace wiring or harness as necessary.