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2011 cbr250r I bought this several years ago it had been in a wreck and the plastics were completely destroyed but it ran fine drove it around for several months then I parked it for at least 3 years.
Now I'm ready to work on it again so I put a battery on it and find out that the fuel pump is not priming and I'm getting no spark. Motor turns over fine.
So I start checking everything. I have power going to the fuel pump relay but it never gets a ground. Also I have power going to the coil but it never gets a ground.
Both of these ground wires go directly back to the ecm so I check them there and they never show ground there either.
I checked all the ecm grounds and the all have continuity to battery ground. Then I checked the peak voltage of the ckp it is within spec and i checked the peak voltage of the coil but it read nothing.
All this lead up to me replacing the ecm because every other test passed and the service manual said replace ecm.
The new ecm made no difference.
Other things to note I am missing the bank angle sensor but it was missing when I bought it and it ran without it before.
I can't think of anything else to check I'm hoping I'm missing something that may be obvious to others.
 

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2011 cbr250r I bought this several years ago it had been in a wreck and the plastics were completely destroyed but it ran fine drove it around for several months then I parked it for at least 3 years.
Now I'm ready to work on it again so I put a battery on it and find out that the fuel pump is not priming and I'm getting no spark. Motor turns over fine.
So I start checking everything. I have power going to the fuel pump relay but it never gets a ground. Also I have power going to the coil but it never gets a ground.
Both of these ground wires go directly back to the ecm so I check them there and they never show ground there either.
I checked all the ecm grounds and the all have continuity to battery ground. Then I checked the peak voltage of the ckp it is within spec and i checked the peak voltage of the coil but it read nothing.
All this lead up to me replacing the ecm because every other test passed and the service manual said replace ecm.
The new ecm made no difference.

Other things to note I am missing the bank angle sensor but it was missing when I bought it and it ran without it before.
I can't think of anything else to check I'm hoping I'm missing something that may be obvious to others.
Possible theft deterrent issue? Fuses check out?

I believe Danno had noted in another post that the ignition assembly is matched to the ECM.

Maybe he will chime in.
 

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Hi Randy! Let's see if we can figure this out.
I have power going to the fuel pump relay but it never gets a ground. Also I have power going to the coil but it never gets a ground.

Then I checked the peak voltage of the ckp it is within spec and i checked the peak voltage of the coil but it read nothing.

Other things to note I am missing the bank angle sensor but it was missing when I bought it and it ran without it before.
Are you measuring coil voltage on same wire? Wondering about contradiction where it has power one moment, but not next.

I think there's an age and sitting-around issue here. Nothing usually fails, but there can be corrosion on electrical connectors. Let's do some testing:

1. Take look at BAS wiring-connector. Or better yet, take photo of that connector and post it here.

2. Key ON, put transmission in neutral. Does neutral light on dash turn ON?

3. Measure resistance of sidestand switch G/O wire to chassis-ground:
a. how many ohms with sidestand UP?
b. how many ohms with sidestand DOWN?

4. Measure resistance of fuel-pump's GREEN wire to chassis-ground. How many ohms?


Do you have or have access to oscilloscope?
 

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Hi Randy! Let's see if we can figure this out.

Are you measuring coil voltage on same wire? Wondering about contradiction where it has power one moment, but not next.

I think there's an age and sitting-around issue here. Nothing usually fails, but there can be corrosion on electrical connectors. Let's do some testing:

1. Take look at BAS wiring-connector. Or better yet, take photo of that connector and post it here.

2. Key ON, put transmission in neutral. Does neutral light on dash turn ON?

3. Measure resistance of sidestand switch G/O wire to chassis-ground:
a. how many ohms with sidestand UP?
b. how many ohms with sidestand DOWN?

4. Measure resistance of fuel-pump's GREEN wire to chassis-ground. How many ohms?


Do you have or have access to oscilloscope?
44513
44514


I misspoke about the coil losing power. I meant that it has 12v on black/blue wire to ground and on light green wire to ground. The light green wire never grounds in order to complete the circuit and spark.
The manual says in part of the troubleshooting to check peak voltage of coil. It says hook positive meter lead to light green wire at coil with coil still connected and hook negative meter lead to ground then spin engine. When doing this the voltage drops from 12 to 10.25. Manual say it should be minimum 100v.


Neutral safety is working light comes on in neutral and off in gear.

Side stand switch is a little funny measures 0.2 ohm or closed when down then as I bring it up it has places where it opens but when up fully it reads 1.4 ohms. So I tried disconnecting it and using a jumper wire and no jumper wire with clutch pulled in. No difference.

Fuel pump green wire reads 0.2 ohm or full continuity to ground. If I measure voltage at the fuel pump relay I have 12v on both black/blue wires but the brown wire for the relay coil never gets a ground.
I have checked by using a jumper wire to ground and the fuel pump relay the fuel pump and the ignition coil all work "manually."
I don't have an oscilloscope.
Thanks for any help.
 

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Ok, let's ignore kickstand switch for now, it's definitely not working right. But it won't prevent starting if your neutral-switch is operational.

To detect ignition-pulses on coil, you really need oscilloscope. That's because grounding pulses are extremely short (<5ms) and will not be picked up by multimeter. On oscilloscope, ground side of coil will have signal like this:


To monitor this signal on ground side, you can also use a 'noid light. It has duration-extending circuitry to flash light long enough for human eye to see. Amazon - noid light. Connect terminals to each side of coil primary.


I suspect main cause of not starting is lack of BAS. With nothing connected, bike will crank, but ECU will not run engine, no fuel or spark. Need to trick it into thinking BAS is connected and vertical. To do that, get short 1" piece of wire as jumper. Strip 1/4" insulation from each end. Jam it into BAS connector to bridge just terminals #1 & 2 on plug (Y/R + R/Bu). Then fold it over onto connector and tape in place. There was probably jumper-wire in there previously, but wasn't secured and it fell out over 3-years of sitting around.

incorrect understanding of physics here, but procedure is correct.
 

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Ok, let's ignore kickstand switch for now, it's definitely not working right. But it won't prevent starting if your neutral-switch is operational.

To detect ignition-pulses on coil, you really need oscilloscope. That's because grounding pulses are extremely short (<5ms) and will not be picked up by multimeter. On oscilloscope, ground side of coil will have signal like this:


To monitor this signal on ground side, you can also use a 'noid light. It has duration-extending circuitry to flash light long enough for human eye to see. Amazon - noid light. Connect terminals to each side of coil primary.


I suspect main cause of not starting is lack of BAS. With nothing connected, bike will crank, but ECU will not run engine, no fuel or spark. Need to trick it into thinking BAS is connected and vertical. To do that, get short 1" piece of wire as jumper. Strip 1/4" insulation from each end. Jam it into BAS connector to bridge just terminals #1 & 2 on plug (Y/R + R/Bu). Then fold it over onto connector and tape in place. There was probably jumper-wire in there previously, but wasn't secured and it fell out over 3-years of sitting around.

incorrect understanding of physics here, but procedure is correct.
So I tried jumping the bas and that made no difference then I tried jumping it at the ecu by back probing the connector this also did nothing. Would I have to some how "reset" the ecu or should it just immediately work when bas is jumped.
 

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Can't comment on your particular model but on the MC 19s we recently had in the shop we found out that the fuel cut relay is interconnected with the ignition and the ECU. Current will get to the relay when you switch on the key but the relay will not activate the fuel pump or ignition coils without engine rotation.When the engine cranks the pulse pickup coils signal the ECU which switches everything on. Yamaha has something similar...the fuel pump will only activate for 3 seconds when you switch on and if there is no engine rotation it will switch off. So, if your carbs are dry you may have to switch off and on to get them refilled if longer than 3 seconds.
 

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Ah yes, engine-rotation required for fuel-pump operation. This came out of FMVSS requirement in... 1992 I think. Some safety feature so that if you're trapped in flipped over crashed car with ruptured fuel-lines, pump won't make matters worse by dumping entire contents of tank onto hot exhaust pipes.

So I tried jumping the bas and that made no difference then I tried jumping it at the ecu by back probing the connector this also did nothing. Would I have to some how "reset" the ecu or should it just immediately work when bas is jumped.
Shouldn't need to reset ECU since it's regular part of operations. Does bring up point about MIL. Does it light up for about 2-seconds when you turn key ON? Then goes out?

Should also check for stored DTC codes. Are there any?

Let's verify BAS hack. Disconnect ECU from connector. Then measure between terminals:

1. measure resistance between #25 & 29, Green/Red & Green/Orange wires. How many ohms?
2. measure resistance between #6 & 26, Yellow/Red & Red/Blue. How many ohms?
 

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Checked the jumper on bas sensor it reads 0 ohms at ecu connector
25 to 29 also read 0 ohms

I'm getting several codes
1, 8, 9, 1-2, 29, 54.
Just started checking them briefly
I'm a little confused on how to interpret what I'm calling 1-2 its 1 slow blink then 2 quick ones
First I checked the 5pin sensor connector and it has 5v between yellow/red and green/white.
Then I checked code "1 map sensor low voltage" wires light green/yellow and green/white reads 4.62v manual says minimum is 4.75v. So I checked continuity to ground on light green/yellow wire it reads 196kohms not sure of the significance so I stopped here.
 

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Checked the jumper on bas sensor it reads 0 ohms at ecu connector
25 to 29 also read 0 ohms
What about 6 to 26 at connector? With ECU disconnected. Yellow/Red & Red/Blue at connector. How many ohms?



I'm getting several codes
1, 8, 9, 1-2, 29, 54.
Just started checking them briefly
I'm a little confused on how to interpret what I'm calling 1-2 its 1 slow blink then 2 quick ones
First I checked the 5pin sensor connector and it has 5v between yellow/red and green/white.
Then I checked code "1 map sensor low voltage" wires light green/yellow and green/white reads 4.62v manual says minimum is 4.75v. So I checked continuity to ground on light green/yellow wire it reads 196kohms not sure of the significance so I stopped here.
One thing in common with all those codes is reference-voltage line VCC that supplies all sensors (although 1 & 1-2 seems mutually exclusive). Short in any of those sensor circuits would result in lower sensor output-voltage. Light-green/yellow output-voltage from MAP-sensor should NOT have any connection to chassis-ground. That would drain voltage going into ECU and tricking it into thinking load is lower than actual. That might be cause of low 4.62v output instead of 4.75v.

1. disconnect ECU from connector
2. measure resistance between #27 light-green/yellow connector and chassis ground.
 

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Discussion Starter #11
6 to 26 reads 0 ohm with ecu disconnected.
27 reads open to ground with ecu disconnected. Reads about 2kohm with ecu connected.
 
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