Diagnosis & Repair Procedure
NOTE:
For better performance and results of this diagnostic procedure, usage of appropriate wiring diagram is recommended. See ENGINE PERFORMANCE
in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
NOTE:
Perform all voltage and resistance tests using a Digital Volt-Ohmmeter (DVOM) with a minimum 10-megohm input impedance, unless stated otherwise in test procedure. Use an ohmmeter to isolate wiring harness shorts or opens.
- If engine system check has been performed, go to next step. If engine system check has not been performed, perform A-4: ENGINE SYSTEM CHECK under SYSTEM TESTS, then go to next step.
- If DTC P0403 was not retrieved along with DTC P0401 or P0402, go to next step. If DTC P0403 was retrieved along with DTC P0401 or P0402. See DTC P0403: EGR FLOW MALFUNCTION SELF-DIAGNOSTIC SYSTEM.
- If SUZUKI scan tool or equivalent is available, go to next step. If SUZUKI scan tool or equivalent is not available, go to step 6 .
- Turn ignition switch to ON position. Using scan tool, check EGR system. See EXHAUST GAS RECIRCULATION under EMISSION SYSTEMS & SUB-SYSTEMS in SYSTEM & COMPONENT TESTING article. If EGR system is operating properly, go to next step. If EGR system is not operating properly, go to step 6 .
- Turn ignition switch to LOCK position. Perform MAP sensor component test. See MANIFOLD ABSOLUTE PRESSURE SENSOR under ENGINE SENSORS & SWITCHES in SYSTEM & COMPONENT TESTING article. If MAP sensor is faulty, repair or replace as necessary and repeat DIAGNOSIS & REPAIR PROCEDURE . If MAP sensor is okay, check for intermittent problem. See INTERMITTENTS in TROUBLE SHOOTING - NO-CODES article. If intermittent problem is found, repair as necessary and repeat DIAGNOSIS & REPAIR PROCEDURE . If no intermittent problem is found, substitute ECM with a known good unit and repeat DIAGNOSIS & REPAIR PROCEDURE .
- Turn ignition switch to LOCK position. Disconnect EGR valve 6-pin harness connector C04. Turn ignition switch to ON position. Measure voltage between ground and EGR valve harness connector C04 terminals No. 2 and 5 (Blue/Black wire). See Fig 1 . If voltage is 10-14 volts, go to next step. If voltage is not 10-14 volts, repair open circuit in Blue/Black wire between EGR valve and main relay. After repair, repeat DIAGNOSIS & REPAIR PROCEDURE .
- Turn ignition switch to LOCK position. Connect EGR harness connector and disconnect ECM harness connectors C51-3 and C51-2. Turn ignition switch to ON position. Measure resistance between ECM harness connectors C51-3 terminal No. 4 (Blue/Black wire) and ECM harness connector C51-2 terminals No. 13 (Green/Red wire), No. 14 (Light Green/Yellow wire), No.15 (Light Green/White wire) and No. 16 (Light Green wire). See Figure . If all resistances are 20-24 ohms, go to next step. If any resistance is not 20-24 ohms, check for open or short circuit in appropriate wire between EGR valve and ECM. After repair, repeat DTC CONFIRMATION TEST .
- Ensure ignition switch is in LOCK position. Perform MAP sensor component test. See MANIFOLD ABSOLUTE PRESSURE SENSOR under ENGINE SENSORS & SWITCHES in SYSTEM & COMPONENT TESTING article. If MAP sensor is faulty, repair or replace as necessary and repeat DTC CONFIRMATION TEST . If MAP sensor is okay, check EGR valve and EGR passage for clog. If clogged passage is found or EGR valve is faulty, repair as necessary and repeat DTC CONFIRMATION TEST . If clogged passage or EGR valve are okay, check for intermittent problem. See INTERMITTENTS in TROUBLE SHOOTING - NO-CODES article. If intermittent problem is found, repair as necessary and repeat DTC CONFIRMATION TEST . If no intermittent problem is found, substitute ECM with a known good unit and repeat DTC CONFIRMATION TEST .