Intermittent Stalling — 2000 Honda CR-V
Hello all !
I have a 2000 Honda CRV, Intermittent stall. Let cool for 10 minutes and fires right up. Duplicated once and lost cycling of power from distributor assy on yel/ Grn wire from ECM. Verified ignition switch not at fault, Alternator charging.
Anyone familiar with these? I just want a second opinion before I condemn ECM.
Top traces are battery voltage at distributor and ignition switch. Yellow is backprobing circuit in question while cranking no start, no spark.
David Check ICM CNTRL KOER Warm Engine at idle Frequency is about 25Hz. Frequency should increase as Rpm increase make sure to keep meter leads away form ign. Wires do a gradual rpm increase and decrease
When the vehicle runs, that circuit toggles from 12V to 0 in a square wave patter, problem is when is stalls and will not start, there is no toggling of voltage on that circuit.
Check the PGMI main relay, pattern failure on high milage/ older hondas
David See if the Icm cntrl drops out at 2500 Rpm
I only duplicated issue once and caught it. When It stalled and would not start, I had no ICM control , but there was over 6.5V at Distributor, does that lead me to ECM ? I can rev and hold at 2500 and ICM control is there. I am suspecting ECM and not a relay since all powers are there and the only thing I am missing is the ICM control?
David Before ruling the ecm i would bench test the ICM module at the zone they still have a bench tester I believe its a JA179 and make sure its test about three times so it heats up....
Thanks, I am looking for an answer to this question: There is voltage on that circuit when concern present, ECM is supposed to pull to ground when cranking to signal ICM to fire correct? So in the capture, I have voltage and no toggle from ECM until it cools. Am I missing something else?
David Yes you correct PWM signal, But like Jim as state ECM are rare in these vehicles I would rule out the ICM module not sure if there some kind of voltage feed back in the icm module or the ECM is not PWM when it heats up.... but I would rule out the ICM module as these are prone to fail under heat.....
Ignition control modules are also prone to fail as you are describing- ECM failures are sorta rare on CR-V's, scope all the outputs from the distributor/ module to the ECM first,
David Take a look at this information.... talks about a input to the ECM for the ICM module...(crankshaft Sensor)
Not likely to be and ecm problem. If it has aftermarket distributor most likely that's the issue, usually the igniter (ICM) and or the ignition coil is what fails 90% of the time. Used good quality oem or dealer parts aftermarket will have you run in circles again. and don't forget the famous main relay. for this age car after you find the problem I would recommend the others as preventive…
I would want to see that TDC, CKP, and CYP (from the distributor) were ALL steady inputs to the ECM, when that ICM drops out.
Geoff I agree with your assessment
The first GIF is CKP, TDC and CYP on start The second GIF is the ign input signal, with a frequency Math channel and TDC on start The third GIF CH A is ICM, CH C coil amps, CH D cmp The fourth is the CKP, TDC, CYP, PSD file on start
Ray Nice 👌 but I have a quick question about the ICM Control circuit David had mention in his review the yellow trace in the scope shows a voltage signal.... And not a PWM signal curious on what kind of strategies is this representing....