IAB System Inspection (Integra B18C1)
IAB control solenoid valve is located on top of intake manifold. See Figure. Before testing system, ensure IAB control valve shaft is not binding or sticking and valve moves smoothly. With engine at idle and IAB control valve vacuum hose disconnected, ensure IAB control valve arm is in contact with upper stop. Reconnect vacuum hose. Ensure IAB control valve arm is in contact with lower stop. If a problem exists, clean linkage and shafts with carburetor cleaner. DO NOT adjust upper or lower stop. If problem still exists, disassemble intake manifold and check IAB valve body assembly.
- Start engine and allow to idle. Disconnect vacuum hose from IAB control diaphragm. Check for vacuum at hose. See Fig 1. If vacuum is not present, go to next step. If vacuum is present, go to step 6.
- Remove vacuum hose from IAB vacuum tank. If vacuum exists at vacuum tank, go to next step. If vacuum does not exist at vacuum tank, repair blockage or vacuum leak between intake manifold and vacuum tank.
- Turn ignition off. Disconnect IAB control solenoid valve 2-pin connector. Turn ignition on. Measure voltage between solenoid valve harness connector terminals No. 1 (Red/Blue wire) and No. 2 (Black/Yellow wire). If battery voltage is not present, go to next step. If battery voltage is present, replace IAB control solenoid valve.
- Ensure ignition is on. Measure voltage between ground and IAB control solenoid valve harness connector terminal No. 2 (Black/Yellow wire). If battery voltage is present, go to next step. If battery voltage is not present, repair open circuit between IAB control solenoid valve and No. 15 ALTERNATOR SP SENSOR fuse (7.5 amp) in underdash fuse/relay block.
- Turn ignition switch off. Reconnect IAB control solenoid valve 2-pin connector. Turn ignition on. Use fused jumper wire to connect ECM connector "B" terminals No. 16 (Pink/Blue wire) and 20 (Brown/Black wire) together. See Fig 2. If the IAB solenoid makes a clicking sound, go to step 9. If no clicking sound can be heard, repair open circuit between ECM harness connector terminal B16 and IAB control solenoid valve. See appropriate wiring diagram in WIRING DIAGRAMS article.
- Increase engine speed to 6000 RPM. Check for vacuum at IAB control diaphragm hose. If vacuum does not exist, system is okay. If vacuum exists, go to next step.
- Disconnect IAB control solenoid valve 2-pin connector. Check for vacuum at IAB control diaphragm hose. If vacuum exists, replace IAB control solenoid valve. If vacuum does not exist, go to next step.
- Turn ignition off. Disconnect ECM connector "B". Check for short circuit to ground between IAB control solenoid valve connector terminal No. 1 (Red/Blue wire) and ECM connector "B" terminal No. 16 (Pink/Blue wire). Repair as necessary. If no problem was found, go to next step.
- Substitute known good ECM and recheck system performance. Cut temporary key from a non-immobilizer key blank and tape donor vehicle key to it backwards in order to deactivate immobilizer system during testing. If symptom disappears, replace ECM.