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Old 12-16-2020, 07:17 PM   #4
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Join Date: Jan 2006
Location: NYC
Posts: 44,710

2003 L-Series 3.0L Sedan
Default Re: New engine/ no crank just clicks

Great, eliminating one problem is progress especially affecting a no start issue.

Presuming your Vue 2.2L using drive by wire throttle (electric throttle, electronic pedal), did you reuse your original throttle body and ecm or mixed parts from the donor engine? GMs Passlock security requires 'marrying' ecm to bcm if these parts are replaced. A security password is learned in a simple 30 minute procedure whether ecm or bcm is replaced. Throttle body replacement requires turning on ignition/no pedal movement, for 30 seconds until a slight hum is heard from throttle being commanded by the ecm in a calibration routine. Once calibration mode is entered (automatically), the ecm commands throttle into several positions and uses the feedback position sensors in throttle to calibrate/synchronize throttle to ecm. All occurring in less than one minute. Afterwards, the ecm positions throttle for starting, Cycle ignition off to end this calibration routine then turn on ignition for startup. This should correct the reduced power mode indicator. Throttle, pedal and ecm are three components that can turn on reduced power mode. If the ecm was replaced, marrying the ecm to the bcm is required to relearn a security password.

The ecm and bcm are married via 10 minute dealer procedure or at home (diy) 30 minute procedure (posted several times in these forums). This relearn procedure is basically cycling ignition on for 10 minutes, cycling ign off then repeating two more times. On the fourth ignition on cycle, the security password is passed on to the ecm from the bcm so the two can work together for Passlock to operate. Passlock security is programmed in the bcm to send either a go or no go signal to the ecm. The steering wheel has a Passlock sensor to detect ignition lock cylinder rotation and ign switch voltages to determine if security is correct or not. When the bcm detects ign lock rotation and ign switch voltages, a go signal is sent to the ecm to allow injector operation. If this security check fails, the bcm sends a no go signal to the ecm. The ecm disables injector operation and turns on the security indicator, flashing quickly.

Testing for fuel pressure at the fuel test valve only checks for fuel pump operation and fuel pressure (strong fuel spray at ignition on time). Injectors are not tested. To test for spark or fuel; remove spark plugs after several starting attempts failed to get the engine to startup. Presuming the security indicator cycles on then off after ignition is turned on, injectors should be operating during starting with fuel pressure forcing fuel thru injectors. Removing plugs should reveal wet, soaked plugs or dry ones. Several starting attempts should have plugs wreaking of fuel to verify injector operation.

If plugs are not wet from injector operation, one injector fuse powers all injectors. This presumes reconnecting the ecm wiring harness was correct. Any doubts; disconnect battery negative and disconnect harnesses for careful examination of bent pins, male/female pins/sockets inadvertently pushed out creating a non electrical connection. All injectors are powered up with 12v on both sides of injector connections (measured to engine ground). One wire from each injector is electronically switched to ground when the ecm commands an injector pulse otherwise both wires to each injector is live with 12v. One member found an intermittent connection due to a pin being pushed out, killing 12v to all injectors. Injectors are wired in parallel for power to all injectors with ignition ON. Injector pulses occur only during engine rotation (starting or running). If plugs are wet, spark is most likely the problem. If plugs are dry then the ecm or crank sensor failed. ECMs rarely fail.

While there are several ways to diagnose EFI system issues, the quickest way may be spraying starting fluid into the throttle body. If fuel is suspect, starting fluid is one way to guarantee manually feeding fuel into the engine and starting up. If the ignition system is working then spark will ignite starting fluid for a brief run. If the engine won't fire up with starting fluid then either the ignition system failed to produce spark or the crank sensor failed. The ignition system has only two parts, the ignition coil pack and the ignition control module sitting on one side of the coil pack. More icm failures occur than coil pack failures (past threads within these forums).

The ignition system has one fuse to power it. A spark test done at home; remove plugs, reconnect them to coil pack connected to wiring, wire plug bases to engine block ground, remove either fuel pump fuse or pump relay, and have someone start the engine while you observe for spark across all plugs.

While these procedures may seem long and drawn out, these are the very best diy troubleshooting procedures with little knowledge of EFI systems. Fuel and spark are needed and commanded by the ecm. Air is presumed ingested without restrictions. Failure of (both) injector operation (no fuel on plugs) and spark tends to point to a faulty crank sensor. The crank sensor operates when the engine turns over, generating precise timing signals (electronic clock) to allow the ecm to operate (fuel pump, ignition system for spark and pulse injectors). No crank sensor signals kills the entire EFI system rendering the ecm as nothing more than an expensive door stop.

Hopefully you're not confused and can attempt some procedures to find either a fuel or spark issue. The starting fluid procedure tests for failure of injector and spark and can narrow this problem to one subsystem failure or crank sensor failure (killing the entire EFI system).
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