Hoping the J35 experts can chime in

Messages
173
Location
Great Lakes
I posted this on the Ody forum and have gotten a lot of views but not a single reply. Hoping someone Like Trav, Clinebarger, The Critic might have an idea. This van has been keeping me busy lately. Body and interior are mint and engine and trans are strong even with the varnish on one side as I have previously posted, plus it has new timing belt, water pump, valve adjustment, fuel pump. Once the kid is off to college it will be time to part with it but need to keep it running a bit longer.

I am leaning toward an intermittent PCM but not sure.

I have read around the forums that the intermittent crank(turns over) but no start is normally caused by relays. In my case I believe it is not the relays as it was one of the first things I eplaced. All the relays related to the PCM and fuel pump it with the new OEM Denso relays that are made in Japan. But I still encounter the problem.

I have a prosumer scan tool indicates no codes and graphing PIDS for all sensors look normal. When the vehicle it is acting up I have tried the fuel pump actuation test from the scan tool and the scan tool reports the fuel pump is running but in reality it is not.

The crank but no start condition NEVER occurs first thing in the morning. Van always starts instantly in the morning, but after the first drive, the condition can randomly happen through out the day. If you wait several hours it will it will resolve itself. It will never just stop while engine is running. But if you turn it off it may not start up again. It will never shut off while driving either.

I looked at the ECT sensors and those all appear to be reporting the correct temperature when warm.

During one of these early episodes I jumped load side of the PGM fuel pump relay and the fuel pump turned on and was able to get the car home.

Also during the crank but no start episodes. I am getting voltage from the PCM which is from A11 of the PCM to the coil side of the fuel pump relay which suggest the immobilizer unit is working.

I have gotten around the problem for now by wiring a toggle switch with a relay on it so the kid can get home. The use of the switch has now been needed every single day for the past week so the problem is getting more repeatable. After the problem happens it can resolve it self in 30 minutes or for sure after 4 hours.

I also cleaned all the grounds 4 or 5 in the engine compartment and and the ground to the block and transmission, a ground by the fuse panel by the drivers left leg and checked the ground to ground voltages and they are all fine.

The immobilizer key in dash shows the correct number of flashes as key is inserted and removed and scan tool confirms it.

I am just thinking of leaving switch but am worried if an accident happened fuel pump would continue to run and could cause a hazardous condition.

Any Ideas would be much appreciated. I would much rather it quit so I could track the issue easier rather then it being intermittent as I only get a short window to trouble shoot. Of course when I am ready to trouble shoot it will not act up.

Any ideas what else I could chase down?

Thanks in Advance!
 
Messages
9,064
Location
Marshfield , MA
Total guess, Either fuel pump relay is bad, or power to it is bad if you can jump the relay and the fuel pump works. On my BMW the 12v source to the relay was fused and a loose fuse would cause intermittent power> There's also a crank sensor that the brain has to see and the brain itself. Eliminate the cheap easy stuff before going after the brain. Please post your progress.
 
Last edited:
Messages
5,383
Location
Fort Worth, Texas
Always include the Year when asking for help like this!!!!

From the description.....I can take a stab at it ('08-'10) I'm guessing??

A11 is a Ground switched circuit.......If it "High" 12vdc.....The PCM is NOT commanding the Fuel Pump Relay on & the 12vdc is coming through the coil of the relay.
Now....There's usually only a few second Prime when you turn the key to Run....Then there will need to be a RPM signal for the PCM to command the pump back on. Circuit should go from High to Low.
 

Drew7a

Thread starter
Messages
173
Location
Great Lakes
Always include the Year when asking for help like this!!!!

From the description.....I can take a stab at it ('08-'10) I'm guessing??

A11 is a Ground switched circuit.......If it "High" 12vdc.....The PCM is NOT commanding the Fuel Pump Relay on & the 12vdc is coming through the coil of the relay.
Now....There's usually only a few second Prime when you turn the key to Run....Then there will need to be a RPM signal for the PCM to command the pump back on. Circuit should go from High to Low.
Sorry it is an 08.

2 few second prime does not happen when intermittent problem shows up.
 

Drew7a

Thread starter
Messages
173
Location
Great Lakes
So just to confirm, if A11 stays high(approx 12v when problem occurs. This means the PCM is not switching to ground and switching transistor in PCM is defective.
 
Messages
763
Location
sw ohio
I posted this on the Ody forum and have gotten a lot of views but not a single reply. Hoping someone Like Trav, Clinebarger, The Critic might have an idea. This van has been keeping me busy lately. Body and interior are mint and engine and trans are strong even with the varnish on one side as I have previously posted, plus it has new timing belt, water pump, valve adjustment, fuel pump. Once the kid is off to college it will be time to part with it but need to keep it running a bit longer.

I am leaning toward an intermittent PCM but not sure.

I have read around the forums that the intermittent crank(turns over) but no start is normally caused by relays. In my case I believe it is not the relays as it was one of the first things I eplaced. All the relays related to the PCM and fuel pump it with the new OEM Denso relays that are made in Japan. But I still encounter the problem.

I have a prosumer scan tool indicates no codes and graphing PIDS for all sensors look normal. When the vehicle it is acting up I have tried the fuel pump actuation test from the scan tool and the scan tool reports the fuel pump is running but in reality it is not.

The crank but no start condition NEVER occurs first thing in the morning. Van always starts instantly in the morning, but after the first drive, the condition can randomly happen through out the day. If you wait several hours it will it will resolve itself. It will never just stop while engine is running. But if you turn it off it may not start up again. It will never shut off while driving either.

I looked at the ECT sensors and those all appear to be reporting the correct temperature when warm.

During one of these early episodes I jumped load side of the PGM fuel pump relay and the fuel pump turned on and was able to get the car home.

Also during the crank but no start episodes. I am getting voltage from the PCM which is from A11 of the PCM to the coil side of the fuel pump relay which suggest the immobilizer unit is working.

I have gotten around the problem for now by wiring a toggle switch with a relay on it so the kid can get home. The use of the switch has now been needed every single day for the past week so the problem is getting more repeatable. After the problem happens it can resolve it self in 30 minutes or for sure after 4 hours.

I also cleaned all the grounds 4 or 5 in the engine compartment and and the ground to the block and transmission, a ground by the fuse panel by the drivers left leg and checked the ground to ground voltages and they are all fine.

The immobilizer key in dash shows the correct number of flashes as key is inserted and removed and scan tool confirms it.

I am just thinking of leaving switch but am worried if an accident happened fuel pump would continue to run and could cause a hazardous condition.

Any Ideas would be much appreciated. I would much rather it quit so I could track the issue easier rather then it being intermittent as I only get a short window to trouble shoot. Of course when I am ready to trouble shoot it will not act up.

Any ideas what else I could chase down?

Thanks in Advance!
Main relay? Thermal expansion causing cracked solder joint(s) on pc board. Reflow solder on joints.
 
Messages
5,383
Location
Fort Worth, Texas
So just to confirm, if A11 stays high(approx 12v when problem occurs. This means the PCM is not switching to ground and switching transistor in PCM is defective.

Good possibility, Though it could also be a connection issue. Where are you back probing at? Might want to command the pump relay on & flex on the PCM connector....Then do a Pin Drag test on that Terminal Pin.

Wiring a Ford Inertia Switch in series with a permanent ground to the pump relay should alleviate your safety concerns, The pump will only run when the Main Relay is activated & the Inertia Switch will open the pump relay ground circuit in case of a collision.
 

Drew7a

Thread starter
Messages
173
Location
Great Lakes
Good possibility, Though it could also be a connection issue. Where are you back probing at? Might want to command the pump relay on & flex on the PCM connector....Then do a Pin Drag test on that Terminal Pin.

Wiring a Ford Inertia Switch in series with a permanent ground to the pump relay should alleviate your safety concerns, The pump will only run when the Main Relay is activated & the Inertia Switch will open the pump relay ground circuit in case of a collision.
Thanks I back-probed, flexing and did the pin dragging. I found a PCM on E-bay for $60 so might try that to see if problem resolved itself.

Never thought about the ford inertia switch! Great idea.

Thanks for the help!
 

Drew7a

Thread starter
Messages
173
Location
Great Lakes
In case you don't already know, you will need it programmed by the dealer, or have access to Honda HDS or a full function scan tool to program your keys to the immobilizer in that PCM.
Thanks for the reminder, I have access to a scan tool that can program the keys to the immobilizer.
 
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