2010 Malibu P0690 Code, No Start (also U2108 & C0897)

Which engine? Did you check to see if power to all other fuses in distribution center?

4 cylinder. And I didn't check all the fuses, but I know for sure the abs fuses and most others were getting power KOEO. There were maybe a couple that weren't but I figured that's normal, as I've seen that on other cars. I imagine some circuits are not powered KOEO, but then again I'm no expert with electrical troubleshooting

Check fuses 2,6,43,44 key on ...also fuses 15,16,21.should have power both sides last 3 hold key in crank position. Use test light connected to battery negative.

See if power to fuses.

Gotcha. Will check and report back. Got sick, so I'm put up for now, but will keep you posted. Thanks!

Hope you feel better.... Keep us posted.

Happy Holidays! UPDATE : using a power probe, determined that all fuses are intact / have power. The strangest thing(s) happened, though: 1. After replacing the crank sensor, we now get a crank sensor circuit malfunction code (P0335). Swapped the old one back in, and it's throwing a P0335 code now too! Wiring harness is clean. No rpm signal on scan tool (had one before) 2. While troubleshooting, (key on engine off) the car's auxillary power just started turning on and off by itself rapidly. At first it would flicker a bunch then stop for a second and repeat. Then it just kept doing it indefinitely. Dash lights, obd port, cigarette lighter all were pulsing. Wiggled every wiring harness in sight, disconnected multiple sensors, nothing stopped the flickering. Things to note: -CKP connector (3-wire) is getting power and ground to 2 pins, nothing from third (signal wire?) -5V reference circuit is intact, although it was jumping between 5 and 6V during the power flickering -Battery voltage was only 10.5V (as low as 6 while flickering) and the flickering seemed to stopped after connecting a battery jumper. -Terminals are snug, no corrosion on them -P0690 code hasn't returned since clearing, but computer codes still present, and only new codes are low voltage / current / power codes (ABS, power steering, body modules) I know this is alot, but it is a very interesting case, and would like some input for the sake of learning. I'm honestly leaning toward a faulty PCM and/or bad battery, but without a wiring diagram, can't call it 100%.

Does car start? Does your scan tool have capability to scan and retrieve codes from all modules? Check battery terminal connections. Load test battery. Autozone will do for free. If all check out then have to disconnect sensors and check 5 volt ref should be between 4.9-5.1 vdc. You have 2 5 volt ref circuits but internally connected inside the pcm. There is a 5 volt regulator inside the pcm that converts battery voltage to 5 volts. Also depending on above readings have to test 5 volt ref circuits at pcm plus ignition and battery voltage feeds and also pcm grounds at pcm. Need tpins to back probe. I can send you pcm pin out chart. Battery and connections must be checked first. Pcm needs steady battery voltage feed and good grounds. Does car start? I have seen weird lighting and other things happen with bad battery. Let me know.

autojoe, thanks for the quick reply -The car doesn't start, but does crank. -My tool does have the ability to scan all modules, all the codes mentioned are what it returns. -Checked battery terminals, reseated them tight and all, no difference The only thing left is to load check the battery and do tests at the pcm. I do have a set of backprobes, so the pinout chart would be very helpful. Also, to clarify, the lights weren't just flickering, but the entire ignition it seems was literally switching on and off! You could hear clicking from relays initiating over and over. Could bad ignition switch wiring cause this? Could the soldering I did on the ignition coil harness cause this? (Battery was disconnected during harness repair, and it did run like normal for two days after that first repair). Thanks! Ken Ken

What wires were soldered? Relays clicking? You stated ignition related how do you know ignition related? P0690 not set maybe because car not started have to look at code enabling setting criteria. Since won't start have to check basics during crank condition spark fuel injector pulses fuel pressure. Coil on plug I assume pull coil and take a grounded test light and test for spark to each coil. Can test for injector pulses with a test light or a noid light. You stated no rpm signal on scan tool during crank. If pcm is not receiving one then you would have no spark or injection pulses.

As far as crank signal too fast for meter to pick up. Hall effect 5 volt digital square wave. Back probe signal wire with plugged in and bump starter keep doing should see low and high may take several bumps of starter high being around 5 volts. Voltmeter gives average not fast enough. Some higher priced min max will capture most will not. Best tool labscope or logic probe. Can do a bypass test while watching scan tool key on engine off. I can explain how to do just need you to unplug crank sensor and see if voltage on signal wire key on engine off. If none 5 volt pull up circuit. Also back probe all three wires at crank sensor 5 volt ref signal and ground while cranking 5 volt ref should not drop be around 4.9-5.1 volts. Ground may be around 2-3 hundred millivolts because the block gets loaded with starter motor current when running want to see under 100 millivolts. I explained above about the signal voltage bumping the starter lows and high voltage. Let me know if any voltage unplugged on crank signal line. We can do a bypass test with a test light. When replacing a crank sensor a crank sensor relearn has to be done with a scan tool or set p0315.

Light green.... 5 volt ref..... Purple..... Ground..... Yellow signal wire..... Colors.

If no voltage on signal wire koeo unplugged take a test light connected to battery positive touch signal wire terminal repeatedly off and on while watching crank signal data pid or rpm signal. See if you have some sort of crank data pid on scan tool says yes no ect. Rpm may not update unless pcm sees a cam sensor signal. If not may have to do bypass test with cranking engine just be careful engine may try to start if does shut off because the signal of the crank sensor will be wrong you are just looking for a reaction. Koeo first may hear relays clicking.

If koeo relays clicking right.... Touch relays with your finger see which relay or relays are clicking.

Probably the powertrain relay is the one clicking. Put finger on it. If so either low voltage on control side or weak pcm ground. Npn driver inside pcm weak or high resistance in the wire from relay to pcm. Just some thoughts. This relay controls voltage to many components.

Wow, thanks for the detailed information! I don't own the car, it's a friend's, so I have to wait until Monday or Tuesday to get in front of it again. I'll try the bypass test and/or backprobing the sensor harness while cranking. I don't have a scope, but my power probe can show single channel waveforms, might do the trick... Just to be sure, sending battery voltage along signal wire won't harm the pcm during the bypass test? Also, I meant that the ignition coil wiring harness was repaired due to broken wires. And the clicking relay was for the low beams, during that power fiasco.

Bcm controls lighting. Use test light for bypass test. Power probe will harm driver inside pcm.

UPDATE: So, went at it again. Checked everything I could think of. PCM is getting power and ground, ground to ground drop tests came out at 0, CAN circuits are putting out signals, ignition voltage present at PCM, injectors have power and pulse, PWR-TRN relay is working.. I'm stumped. A couple of interesting things to note: -Injectors have power and pulse, and there is fuel pressure, but the pulses were fat. Like a full second or so. I figured that is abnormal, but I'm not sure. I've always seen rapid pulsing with injectors. -CKP harness seems healthy. The sensor itself generates voltage waveform on signal wire when tested plugged in KOEO with a magnet (backprobed). However, it still does not produce an RPM signal on scanner (BlueDriver) when installed in engine, and there is no signal waveform when cranking.. -On PWR/TRN relay circuit.. I get power KOEO at control and load side feeds (pins 86/87)) as expected, nothing from control side switch (pin 85).. But for some reason load side switch (pin 30 - routes power to injectors, O2, MAF/IAT, ignition coil, & ignition voltage feedback circuits) is hot with key OFF, PCM unplugged at fuse block.. Not sure what to make of that, PCM unplugged nothing on that circuit should be getting power, right? All of those are relay fed, PCM grounded/controlled as far as I know!