I got a 2001 olds silhouette, 3.4, with p1374. Checked ecm and replaced cps on the side of the block. ran great for about 4 miles, then started doing what it was doing originally and that is stumbling and then stalling. Had to pump the gas twice to get it to start, which is also a previous problem. RPM gauge jumps all over just before it stalls. Only thing new is the dash light said hot coolant temperature. Appreciate help on this one... Should I replace the 2nd crank position sensor that is behind balancer?
DTC P1374
The 3X reference signal is produced by the ignition control (IC) module. The IC module calculates the 3X reference signal by dividing the crankshaft position (CKP) sensor 7X pulses by 2 when the engine is running and when the CKP synchronizing pulses are being received. The powertrain control module (PCM) uses the 3X reference signal to calculate the engine RPM and the crankshaft position at engine speeds above 1600±150 RPM. The PCM also uses these pulses to initiate injector pulses. The PCM compares the 3X reference pulses to the 24X CKP pulses and the camshaft position (CMP) sensor pulses. If the PCM receives an incorrect number of pulses on the 3X circuit, a DTC P1374 will set and the PCM will use the 24X CKP reference circuit for fuel and ignition control. The engine will continue to start and run using only the 24X CKP and the camshaft position sensor signals.
Diagnostic Aids
• DTC P1374 can be caused by secondary components leaking high voltage into the IC module.
• Inspect for the following conditions:
- Incorrect harness routing near secondary ignition components
- Ignition coil arcing to wiring harness or IC module--Inspect the ignition coils for the following conditions:
• Cracks
• Carbon tracking
• Other signs of damage
- Ignition coil arcing to wiring harness or IC module--Inspect the ignition coils for the following conditions:
- Secondary ignition wires arcing to wiring harness
I would sugest you take your vehicle to a qualified repair shop an have it diagnosed , but i can tell that's not your way , is it . We diagnose not replace part's .
Replace the IC module. Refer to Ignition Control Module Replacement .
Did you complete the replacement?
Go to Step 11
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10
Replace the PCM. Refer to Powertrain Control Module Replacement .
Did you complete the replacement?
Go to Step 11
If it starts an runs it's not the crank sensor behind the crankshaft pulley .
Testimonial: "Replaced the ICM with a known good one, test drove it and started bucking less than a half mile, and stalled when I stopped. Looks as if I need to check wiring harness and test coil packs which show no damage and no arching..."
By the way, after resetting codes the same code came up twice, one as mil, the other as pending.
I found bad plug wires on it, replaced all, started and ran great after 10 starts. took it for test drive, did fine, sent it back to owner to put up for sale, owner asked me if I would clean the inside out, went to pull it around back, n start and had to pump gas to get it going, yet would not stay running. What the heck???????????
With the rpm gauge jumping all over (and sometimes the speedometer) is it possible the ignition switch key which has a chip in it, is what may be what is causing this issue?
Did you check the mass air flow sensor , Have a scan tool that can look at engine sensor data .
Do not have scan tool. I have an obd I and II reader yet I don't think it will read engine sensor data other than what is stored in the freeze frame.
I unplugged the mass sensor when it was running and it didn't affect the engine rpm at all. Which doesn't seem right???
No , that's right , doesn't need it to run . GM vehicles are the only ones that work like that. The thing to do would be look at mass air flow sensor data , an fuel trim's as well . Without doing that we'd just be guessing .
My OBD will give me the fuel trim data at the time the code was set and I'll get that and post it soon. This comes from the freeze frame data.
You could check out videos on you tube mass air flow testing
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I would check grounds. RPM's jumping is normal (Kind of) when stalling. Speedo is not.Opening the throttle to start, you might want to pull a spark plug or two and see if they are wet from fuel. Might want also check the electrical plugs On the ICM, cam sensor, or anything that pops a code. The connectors inside the plug will start spreading and loose contact. Try the wiggle test yet? It really needs to be on a scanner to look at what it's doing when it stalls. Code readers don't give all the info you need.
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