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Discussion Starter · #1 · (Edited)
Hi,

I'm looking for any other input on what could be the causes of an P1445 - Bypass Contactor issue.

Problem Initiation:
Took a 200 mile trip to visit family with no issue. There are large bluffs on the far end of the trip, and I used MIMA-CL for 25% Assist/Regen in the hills.

On the way back, and on flat ground, I got the first P1445. I have a ScanGauge II in the car and could check to see what caused the Engine Trouble Light.

Side Note:
I do a lot of Engine Off Coasting, and typically key off/on to save the IMA battery, which runs down faster than the 12V battery.

So here we are on the trip back with a town coming, so I key off/on and run on the 12V. Come to a complete stop, turn the ignition key, and .... what, the 12V starter is turning over the engine, rather than the IMA.

An immediate IMA light, and check engine light.

Since that time:
When I first start the car, it will start from the IMA with no issue at all. If I key off/on, then I get the P1445 immediately.

Reset the IMA fault by pulling the fuse inside the driver area. Not sure which one, but I have a tab "fiberglassed" to the fuse, so I simply reach up and pull that fuse.

Additional Info:
If I start the car with the IMA, and do not key off/on the entire drive home, everything works fine. No issues.

Once I key off/on, that's when I get the IMA and have to pull over and reset it by pulling the fuse.

Historical Data:
I searched and read every single post regarding P1445, and got the following summary data:

Bypass Contactor - need to replace
100A Fuse - one instance where this caused P1445
Wiring - several discussions about faulty wiring
Connectors - several comments about cleaning contact surfaces

What do you think??

Thanks, Jim.
 

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Hi,

I'm looking for any other input on what could be the causes of an P1445 - Bypass Contactor issue.

Side Note:
I do a lot of Engine Off Coasting, and typically key off/on to save the IMA battery, which runs down faster than the 12V battery.

Historical Data:
I searched and read every single post regarding P1445, and got the following summary data:

Bypass Contactor - need to replace
100A Fuse - one instance where this caused P1445
Wiring - several discussions about faulty wiring
Connectors - several comments about cleaning contact surfaces

What do you think??

Thanks, Jim.
Each time you turn the key on the Bypass Contactor and the Bypass Resistor are switched in just before the main contactor kicks in to reduce the instantaneous IMA battery current that would flow while charging of the IMA capacitors etc if only the main contactor was used.

Both the contactor and resistor are mounted on the IMA Junction board. So it sounds like the contactor or the resistor may be where the problem is (assuming the contactor is getting the command from its control box.

Perhaps the gird charging connection to the Bypass Resistor has come off the resistor and the resistor is not in the precharge circuit anymore? The P1445 seems to be a specific test for the correct operation of the precharge circuit.

If that's not the case then the resistor could be open or the contacts on the Bypass contactor may need cleaning since you are causing it to operate much more than normal.

Why it only happens when you turn the key OFF and back ON is the mystery. (Maybe it's the cars way of telling you not to do that. :rolleyes:

I'd open the IPU box and check the two contactors and resistor wiring. If you listen carefully you may be able to hear each contactor clicking in. But the time between each of them energizing will be very short.

I seem to remember a thread about turning the key OFF or not while drifting. Perhaps it would be better to kill the engine with a relay on the 12V supply line to the injectors? Although that may throw some other MIL.
 

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Discussion Starter · #4 ·
So if you don't key/on off the car works normally on several drive cycles and no ima errors?
Hi Peter,

Yes, exactly as you said above.

I have cycled the car at least five times now, with no IMA issues at all. That is, as long as no key-off-on is done.

I did get a check engine light (P1445) this morning, with no IMA light. Reset the error with the ScanGauge.

Jim.
 

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Discussion Starter · #5 · (Edited)
Each time you turn the key on the Bypass Contactor and the Bypass Resistor are switched in just before the main contactor kicks in to reduce the instantaneous IMA battery current that would flow while charging of the IMA capacitors etc if only the main contactor was used.
Thanks olrowdy01, that is great information to know. I was scratching my head, why Honda would go through the extra trouble of putting in a second contactor and resistor in that place.

I read through the manual quite a few times trying to understand the issue, but it simply was not clear to me why the extra components there.

Now it makes sense.

....Perhaps the gird charging connection to the Bypass Resistor has come off the resistor and the resistor is not in the precharge circuit anymore? The P1445 seems to be a specific test for the correct operation of the precharge circuit.
I will certainly get a close look at all this, as the battery pack needs to come back out this summer for several items, and the contactor is one of them.

.....If that's not the case then the resistor could be open or the contacts on the Bypass contactor may need cleaning since you are causing it to operate much more than normal.
I will check this in detail, and see if the contactor can be taken apart for inspection/cleaning. I will look at the primary contactor as well, if it comes apart.

.....I seem to remember a thread about turning the key OFF or not while drifting. Perhaps it would be better to kill the engine with a relay on the 12V supply line to the injectors? Although that may throw some other MIL.
I do have a FAS board in the car from Mike, so I use that, but key-off when I coast a long ways and do not want the DC-DC on for that length of time. I will have to try and wire a DC-DC off switch so the contactors do not take a beating.

Thanks for the nice response.

________

I will report back on this issue after the summer, as the car is jacked up for work on an automatic grill block, and several items in the IPU. Been waiting to do the grill block for several years now. Hopefully it will really help in the winter. See the post below for more detail on why.

http://ecomodder.com/forum/showthread.php/howto-maximize-fuel-economy-29047.html

Jim.
 

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Thanks olrowdy01, that is great information to know.

Your welcome. I'm glad to share what I know or can find by doing some searching in the Insight documents to help people out. I also learn more about the car while doing the search etc.

I do have a FAS board in the car from Mike, so I use that, but key-off when I coast a long ways and do not want the DC-DC on for that length of time. I will have to try and wire a DC-DC off switch so the contactors do not take a beating.
Jim.
If there's a relay on the FAS board with extra contacts you can just use them to control the DC-DC in addition to the actual FAS function. Or add another small relay for the DC-DC. The relays really don't draw that much current. It's the contacts that have to be rated for the current draw of the controlled device.

I did a search in the advanced_diagnostic.pdf under MIL P1445 and I found something (that I underlined) that might explain why you get the P1445 and the car starts on the 12v system when you turn the key back on. Why this happens only after the first key ON is still a mystery unless perhaps heat is getting into the act. A WAG might be that one of the contactors has burned contacts that don't quite complete the circuit after the IPU gets warmed up.

-------------------------------------------------------------------
Fig. 157: Bypass Contactor - Circuit Diagram General Description

The high voltage contactor between the battery module and the motor power inverter (MPI) module is turned on to activate the integrated motor assist (IMA) system after turning the ignition switch on. Before turning the high voltage contactor on, the bypass contactor is turned on and the motor drive module (MDM) condenser is charged gradually by current limited by the bypass resistor. When the difference between the voltage on the MPI module side and the battery module side is within a set range, the high voltage contactor is turned on, then the bypass contactor is turned off.

If the difference between the voltage on the MPI module side and the battery module side is out of a set range for a specified time after the bypass contactor is turned on, a malfunction is detected and a DTC is stored.

There is a chart here that doesn't show up in the cut and paste I did.
2006 Honda Insight
2006 ENGINE PERFORMANCE Advanced Diagnostics - Insight
MONITOR DESCRIPTION CHART
ENABLE CONDITIONS CHART

Malfunction Threshold
The difference between the voltage on the MPI module side and the battery module side is 37 V or more for at least 2 seconds after the bypass contactor is turned on.

------------------------------------

If the Precharge contactor/resistor circuit isn't working correctly the voltage would be high which would trigger the MIL, the main contactor wouldn't be energized and the car would then have to start on the 12v system because the IMA battery isn't switched on by the main contactor.
--------------

The schematic which is part of that P1445 description shows the precharge resistor not on the battery side of the Precharge Contactor. I believe that is a mistake in the schematic because if was wired that way we wouldn't be able charge the IMA battery using a grid charger with the key off. Both contactors are shown energized at the same time which isn't correct either; except for a slight overlap period.

The Honda technical manual shows the resistor on the battery side of the contactor in a rough drawing; which would allow the grid charger to work.
 

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So lets confirm the sequence of events.

1) Driving along at say 60 mph and decide to coast down to a stop?
2) Into neutral and turn off ignition?
3) Coast down to a stop?
4) Turn car back on and into first hopefully with IMA start but error pops up?

We know what causes the DTC to appear, the voltage difference between the mdm and battery side in the short time <2s between the bypass contactor and main contactor engaging.

So what is causing that in your sequence of events?

IMO the voltage difference/fluctuation must be on the MDM side as the battery is a huge buffer on its side and it's voltage will not fluctuate wildly unless under huge assist/regen.

So what is causing the mdm capacitor pre-charge sequence to fail.

As suggested the bypass contactor could be lazy or damaged, ditto the bypass resistor.
They are easy to replace with other parts.

I would attach a voltmeter (preferably with some sort of logging capability) to the top main battery terminals (this is the mdm side) and watch it carefully during your coast down/start sequence and try to trigger the code.

Compare that with just turning the car on/off and starting it sat on the drive.

Can you trigger the code sat on the drive?

If the voltmeter takes a long time (~2s) to get within ~37v of the battery voltage during your post coast down start sequence
then at least we can confirm the error is correct.
 

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P1445 As Well

Hey there,

I got a P1445 and IMA light as well, I didn't realize it was outside of the battery. I swapped my battery packs and still had the issue.

Do you have a link to replacing the contactors, or what they look like? Are there any items that should be checked in case its not the contactors (one of the posts mentioned that you would not get only a P1445 with missing connections).

Thank you for your help!
 

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Discussion Starter · #9 ·
.....I did a search in the advanced_diagnostic.pdf under MIL P1445 and I found something (that I underlined) that might explain why you get the P1445 and the car starts on the 12v system when you turn the key back on.....
Thanks for the additional info!

Jim.
 

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Discussion Starter · #10 ·
....I would attach a voltmeter (preferably with some sort of logging capability) to the top main battery terminals (this is the mdm side) and watch it carefully during your coast down/start sequence and try to trigger the code.

Compare that with just turning the car on/off and starting it sat on the drive.

Can you trigger the code sat on the drive?

If the voltmeter takes a long time (~2s) to get within ~37v of the battery voltage during your post coast down start sequence
then at least we can confirm the error is correct.
Peter,

I currently have a trickle charge point located in the picture below.

The same as what Mike D had on his website several years ago. Is this what you are referring to "this is the MDM side"?

Picasa Web Albums - Jim - Battery Trick...

I currently do not have a voltmeter with data acquisition, but since the bypass contactor is $65, maybe this project would justify the cost.

Will try to get some voltage readings with the multimeter hooked up.

Jim.
 

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Discussion Starter · #11 ·
.....Do you have a link to replacing the contactors, or what they look like?....
Hi,

The bypass contactor is located where the "plus" arrow is pointing to in the picture below.

The white resistor directly below the same arrow is the bypass resistor.

Picasa Web Albums - Jim - Battery Trick...

I plan on pulling the entire pack to get access to this area.

Hope this helps, Jim.
 

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Discussion Starter · #12 ·
Update:
I'm starting to suspect that the P1445 is NOT a contactor issue at all, but the IMA battery.

Details:
During the road trip to LaCross, the IMA was used pretty heavily in the hills. While I have a fan Hi/Low switch at the back of the IPU, I did not use this during driving in the hills due to it's location.

On the way back home, I got the P1445.

Things Learned Thus Far:
1) Do not rely on the BCM to properly run the fan to keep the pack from getting too hot.

1a) The fan switch will be moved to the dash.

2) Getting a P1445 does not necessarily mean one of the contactors is bad. In my case, I do not believe this is true.

3) Ambient temperature changes how/when I get a P1445.

3a) Cooler temperatures cause no issue at all (60F outside).

3b) 80F temps can start showing issues, especially if Regen/Assist are used and the car has been sitting with the windows closed.

3c) FASing by using the key-on-off sequence does not always cause a P1445. It seems to vary based on battery temp, but as of now, I have no way to measure this directly, just an observation based on driving for the past two weeks, with variable temps.

3d) On warmer days, it's definitely harder to Regen with MIMA, and Regen cuts out at a higher speed in each gear. With 60F temps this morning, the car was back to normal.

All the evidence seems to indicate BATTERY not Contactor.

Jim.
 

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Could be heat affecting the battery or heat affecting the contactor causing an intermittent issue.

The P1445 is quite specific. Replace the bypass contactor and see what happens.
 

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Update:
I'm starting to suspect that the P1445 is NOT a contactor issue at all, but the IMA battery.

Details:
During the road trip to LaCross, the IMA was used pretty heavily in the hills. While I have a fan Hi/Low switch at the back of the IPU, I did not use this during driving in the hills due to it's location.

On the way back home, I got the P1445.

Things Learned Thus Far:
1) Do not rely on the BCM to properly run the fan to keep the pack from getting too hot.

1a) The fan switch will be moved to the dash.

2) Getting a P1445 does not necessarily mean one of the contactors is bad. In my case, I do not believe this is true.

3) Ambient temperature changes how/when I get a P1445.

3a) Cooler temperatures cause no issue at all (60F outside).

3b) 80F temps can start showing issues, especially if Regen/Assist are used and the car has been sitting with the windows closed.

3c) FASing by using the key-on-off sequence does not always cause a P1445. It seems to vary based on battery temp, but as of now, I have no way to measure this directly, just an observation based on driving for the past two weeks, with variable temps.

3d) On warmer days, it's definitely harder to Regen with MIMA, and Regen cuts out at a higher speed in each gear. With 60F temps this morning, the car was back to normal.

All the evidence seems to indicate BATTERY not Contactor.

Jim.
Jim,

The contractor is likely sticking more when it's hot. P1445 means that the car detected the contact engaged when it was supposed to be disconnected.

Joe
 

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Discussion Starter · #15 ·
Could be heat affecting the battery or heat affecting the contactor causing an intermittent issue.

The P1445 is quite specific. Replace the bypass contactor and see what happens.
And....

Jim,

The contractor is likely sticking more when it's hot. P1445 means that the car detected the contact engaged when it was supposed to be disconnected.

Joe
Thanks guys!

I will be sure to check this when the IPU is opened up soon.

Jim.
 

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And....



Thanks guys!

I will be sure to check this when the IPU is opened up soon.

Jim.
Hi Jim,

Apologies for opening an old thread but did you ever get to the bottom of this? I'm getting occasional P1445s when I stop and try and restart (it happened when I stalled the other day) and am thinking it's the bypass contactor sticking.

Cheers,
BenR
 

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This can happen if you key on/off very quickly.
I'm having the same issue in my cvt. Weird I swapped the battery from my 5 speed into the cvt and it didn't work-got the ima light. So how can it be the contacter.
When swapped it back into my 5 speed it worked fine. I did hear a click come from the cvt battery when in my 5 speed before I got ima light. But that can't mean the junction board is the problem if the 5 speed junction board had the same issue when it was in in the cvt. The cvt just wouldnt reguster any bars or evrn try to charge it . So what else could it be ? Confused. I ordered another junction board from fleabay . The seller said it came from a k swap so it was working fine. I'll see how it goes when it comes. I drive the 5 speed daily so the battery was charged up before the swap and the cvt was grid charged to 175.
 

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P1445 As Well

Hey there,

I got a P1445 and IMA light as well, I didn't realize it was outside of the battery. I swapped my battery packs and still had the issue.

Do you have a link to replacing the contactors, or what they look like? Are there any items that should be checked in case its not the contactors (one of the posts mentioned that you would not get only a P1445 with missing connections).

Thank you for your help!
Did you fix your issue yet??
 
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