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Discussion Starter #1
Greetings,
Brand new to the forum, very mechanically inclined, and haven't worked on an ATV in 30 years. I was surprised that they were fuel injected now. My buddy dropped off his 2007 machine, a factory service manual, and asked me to get it running. I guess he had issues with it stalling. I have been reading all your great posts for help..... but I need more wisdom from you Grizzly experts.
1. The TPS - in diagnostic mode it reads 2 w/o throttle and 10 w full throttle. I loosened the TPS to adjust its angle and the readings only changed by a number or two. Clearly out of specs per the service manual. However, resistance of TPS and input voltage of connector are within specs. Although its not my money I'm spending, I would hate to buy a TPS and it not be the needed part. Any ideas?
2. I called the dealer with the VIN and they said there were two bulletins on the machine but had expired. Do they really expire? My buddy was never notified of either issue. I do know he has the old style rollover valve, per bulletin AT2008-006
3. Anybody have any info on Bulletin AT2008-004 Diagnosing Drivability or Unstable Idle Conditions – 2006~2007 YFM70RV/W (Raptor 700R Models); 2007 YFM7FGPW (Grizzly 700 FI Models). I heard about it while googling but I would like to read up on it.

Thank you for all your help and expertise
Tim
 

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I would say to contact the user @dezz, but he will be along to the thread soon. Yamaha tech, very knowledgeable, and very patient. There are some other guys who might be able to help you out, but I wouldn't know who else to tag exactly. He has helped me with many issues.
 

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I am not a Yamaha Tech. Used to work at a Yamaha dealer, but that was in the early 2000's...lol.
I still on ATV's all the time.

Service Bulletins do time out. If I remember correctly all service bulletin from that long ago are expired years ago.

Unfortunately I got nothing else to add to this thread. Wish I did.
Reogem should be able to help though. He'll be by guaranteed.
@reogem
 

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Sorry about that. I have had quite a few guys tell me that about you. Nice to clear the air.
 

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Hey...flint357..Welcome to GC from Wisconsin.

I would say the TPS is toast.
But...
You should check the TPS resistance with it disconnected 3.1-5.7 ohms.
Check over the wires for fraying, clean the connector.
Also check the voltage .63-.73 set it closer to .68-.69 with the throttle closed.
 

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Discussion Starter #6
Update on no start situation

Greetings and thank you for your responses. Here is an update on the no start problem with my friends Grizzly. I have followed the diagnostic flow chart in the Service Manual and replaced the TPS (and adjusted it per reogem), updated Rollover Valve, and replaced Lean Angle Sensor. It still will not start. I can keep it running with starting fluid.
With ignition on, the instrument cluster shows Fault Codes 13, 15, 41. No Er Fault Codes
When cranking over, the Engine Trouble warning light flashes.
In Diagnostic mode, I get the following data: D01=0 and no change with throttle movement; D03=0 and no change when cranking over; D05=10; D06=6; D07=0; D08=0.0 and no change when sensor is tipped; D09=12.3; D21=On; D30=passed actuator test; D36=passed actuator test; D50=passed actuator test; D51=passed actuator test; D60=0.0; D61=22,30,46; D62=6; D70=0.
I do not want to just randomly throw parts at this machine but I think the only other thing it could be is the ECM. I’d hate to have the owner purchase an ECM just to have it not start.
Is there a way to bench test the ECM? Any other things I should consider? I need another ECM from an 07-08 Grizzly just for diagnostic purposes.
Your wisdom and comments are greatly appreciated.
Thank you all again. Tim
 

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@flint357, welcome to GC from Maine. Wish I could help, but when it comes to that kind of stuff I probably would have a better chance of understanding it if it were written in Chinese, LOL!!!
 

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The TPs, LAs, ATs all have at least one wire in common with each other. Check fuel injection fuse #9. Trace your wires looking for faults. Check you connectors for bent pins and proper seat.

No D54 test?
 

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Discussion Starter #9
Greetings to you to mainehunter. I’m beginning to think that learning Chinese in a North Korean classroom would be easier than fixing this machine.
Reogem… there is no D54 callout on this unit. Not even listed in the manual. I googled it and came up very few hits but a mention about an ISC (idle speed control?).
Continuity on every fuse, including #9 tested good. Each sensor you mentioned is getting voltage. TPS, LAS, and ATS all share the B/L (negative- black/blue) and L (blue) circuits. Is the L (blue) circuit the 12-volt feed circuit to each sensor? I will test continuity on all these circuits from the ECM connector to the sensor connector. Each sensor also has another wire (positive wire called out to test sensor voltage), which feed into the ECM via its own terminal. I will check these as well.
Any other suggestions?
Do you know if a Yamaha dealer would have a machine to bench test ECMs? A new ECM is @$500 online and I would hate to have the owner purchase one and it still not run. However, if I take it to the dealer, they will charge me @$700 for the ECM and plug it right in, and give the machine back to me to bolt the plastic back on. I'm betting that the ECM is faulty, but that is a lot of money to bet on.
Once again….. thanks to everyone that took the time to read this and ponder my dilemma.
Tim
 

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Welcome to GC.
 

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Discussion Starter #11
reogem... I tested the TPS, LAS, and IAPS (Intake Air Pressure Sensor) circuits. All these sensors share a black/blue wire and blue wire that go to the ECM. Each sensor also has a third wire that goes into the ECM. Per the schematic, all 5 wired feed directly into the ECM. Therefore, I should get continuity from the ECM connector to each sensor connector.

Testing continuity I got the following results:
TPS, LAS, and IAPS black/blue connector wire to ECM terminal = continuity
TPS, LAS, and IAPS blue connector wire to ECM terminal = no continuity
TPS yellow connector wire to ECM terminal = continuity
LAS yellow/green connector wire to ECM terminal = continuity
IAPS pink connector wire to ECM terminal = continuity

Am I missing something or do I need to start cutting into the wiring harnesses to find an issue with the blue wire?
 

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.......TPS, LAS, and IAPS blue connector wire to ECM terminal = no continuity.....


Am I missing something or do I need to start cutting into the wiring harnesses to find an issue with the blue wire?
Did you test the blue wire from each connector back to the ECM?

What about the blue wires to the intake air temp sensor and the speed sensor? Dead also?
 

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Discussion Starter #13
I just got in from the cold. Rechecked the circuits and have this:

TPS, LAS, IAPS, IAT, SS black/blue connector wire to ECM terminal = continuity
TPS, LAS, IAPS, SS blue connector wire to ECM terminal = now have continuity
TPS, LAS, IAPS, IAT, SS black/blue (ground wire) = continuity between each sensors’ connector, the ECM connector, and with battery ground
TPS, LAS, IAPS, SS blue (power) = 5 volts of power with ignition switch on.

TPS yellow connector wire to ECM terminal = continuity
LAS yellow/green connector wire to ECM terminal = continuity
IAPS pink connector wire to ECM terminal = continuity
IAT brown/white connector wire to ECM terminal = continuity
SS white connector wire to ECM terminal = continuity

So basically, there is continuity among all the grounds, all the positive wires, and all the signal wires to the ECM connector. All sensors are getting 5 volts thru the blue wire when the key is on.

I’m concerned that the blue wire now has continuity, as it didn’t before I cut into the harness and I am 99% certain my probe was in the connector when checking continuity. I cut into the wiring harness and found no broken wires. I’m about 25% convinced there is an internal break and when I put the components back together, the circuit was reopened. However, I’m 75% convinced that the ECM is bad.

Your thoughts?
 
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