DTC P1349: VARIABLE VALVE TIMING SYSTEM MALFUNCTION
Possible causes are:
Incorrect valve timing.
Defective VVT OCV.
Defective VVT controller assembly.
Diagnosis & Repair
1. Check valve timing. If problem does not exist, go to next step. If problem exists, repair as necessary.
2. Start engine and allow engine to idle. Note idle speed. Disconnect Variable Valve Timing (VVT) Oil Control Valve (OCV). VVT OCV is located on front cylinder head, next to intake manifold. Engine idle speed should not change. Using jumper wires, apply battery voltage and ground to VVT OCV terminals (component side). Engine should idle rough or stall. If VVT OCV operates as specified, go to next step. If VVT OCV does not operate as specified, go to step 4.
3. Turn ignition off. Connect VVT OCV harness connector. Access ECM behind glove box. Using oscilloscope, backprobe ECM harness connector and connect oscilloscope between terminals No. 10 Red/White wire) and No. 23 (Red/Black wire) at ECM harness connector E7. Start engine and allow engine to idle. Ensure oscilloscope pattern is as shown in illustration. As engine speed is increased, waveform frequency ("A") should lengthen. If waveform pattern is as shown, go to next step. If waveform pattern is not as shown, replace ECM.
4. Check VVT controller assembly for proper operation. If problem does not exist, go to next step. If problem exists, replace VVT controller assembly and go to next step.
5. With VVT OCV removed, connect a fused jumper wire between positive battery terminal and terminal No. 1 at VVT OCV. Connect another jumper wire between negative battery terminal and terminal No. 2 at VVT OCV and note VVT OCV plunger operation. With battery voltage applied, plunger on end of VVT OCV should extend. Disconnect a jumper wire. Without battery voltage applied, plunger should retract. If VVT OCV operates as specified, go to next step. If VVT OCV does not operate as specified, replace VVT OCV and go to
6. Check blockage in VVT OCV. Check oil check valve and oil pipe located under VVT OCV. If problem exists, repair as necessary. If problem does not exist, go to next step.
7. Install remove components all and connect all disconnected harness connectors. Using scan tool, clear DTCs. Start engine and allow engine to idle. Turn ignition off. Turn ignition on and check for DTCs. If DTC P1349 is not present, no problem is indicated at this time. DTC may have been set because of a foreign object that was temporarily caught in engine oil system but after a short time
system returned to normal. If DTC P1349 is present, replace ECM.
Images (Click to enlarge)
Tuesday, July 31st, 2012 AT 1:13 PM