Prius wouldn't start

probably a bad combo meter

 

call these guys, the slash is a link> (/)

 

If you have a friend or family member that's good at soldering. You simply pull the combo meter (aka: speedometer) out of the dash and replace the capacitor on the board. Very easy fix! Also this problem usually is intermittent at first, so it's easy to procrastinate on.

 

If it’s intermittent, just do this, takes one minute

 

How do you know that?

 

Problems with the spark plugs will cause the engine to misfire (run "roughly" and turn on the "check engine" light). It won't affect powering up the car.

What you are describing matches a common failure mode for the the Combination Meter (the instrument cluster or "speedo"). There is a bad electronic component (capacitor) on the circuit board that can disrupt function of a computer processor in the CM.

The car needs the CM to work in order to power on and off correctly.

If using a booster allows you to power up, you should measure the voltage of the 12V battery before you use it. A Prius doesn't need lots of power from the 12V to turn on (all the heavy lifting of starting the gasoline engine is performed by the High Voltage system). (you said the 12V tested "ok")

A healthy 12V reads 12.6-12.8V with the ignition OFF. Most of the time, it can still power up at 11.5-12.0V (but the battery is weak and should be charged and tested).

My point is that when the CM is having problems, changing the voltage of the 12V system up or down slightly can sometimes make the CM (and the car) turn on. This problem isn't going to fix itself.

Posted via the PriusChat mobile app.

 

if a jump pack works, it's the battery

 

a jump pack cannot overcome a bad combo meter

 

Is this the PriusChat version of rock, paper, scissors?

 

hopscotch

 

From my reading of many reports related to this issue, it seems that a CM with a failing capacitor, a higher 12 V voltage makes the CM fail-to-start problem occur more often. I think that is why all the 'secret' workarounds appear to work (at least initially) as they, in essence, lower the 12 V voltage. Good for getting the CM to work. Very bad for the 12 V battery in the long run.

 

Well, Gen2's don't have EGR coolers or head gasket problems, so we have to do something to stay occupied.

Posted via the PriusChat mobile app.

 

I'll agree with that. Causing an up or down transient, even if minor, at the CM power source voltage can be enough to "jog" the circuit into working. Kind of like thumping an old style ICE starter motor when they start to fail. The mechanical thump agitates the motor brushes enough so that they make contact again. On the Gen 2, the electrical "thump" of screwing with a bunch of switches and buttons provides the agitation. AND, just like the old starter motors, that 'thump' eventually just doesn't work any longer.

 

Just to clarify, the $75 is a core charge, not a shipping fee. They refund the core charge when you return your defective core.

 

The rear hatch problem may not be related to the CM. In my case a few months ago I noticed was a similar and more frequent problem with my 2007 rear hatch. As it turned out the actuator had gone bad. Changing it out is a five minute exercise with one cable clip and three bolts. A new OEM one is very expensive $300 and no aftermarket options exist for the rear hatch, although there are many for the other door actuators. Used ones on eBay are $70 or so. I was able to get one for the rear hatch from a junk yard for $12 or so. I was reluctant to buy one since I figured it might be bad too. As it turns out that one from the junk yard was like new probably had been changed previously recently by dealer.

 

Whether it is the CM or the latch actuator is quite easy to distinguish. If it is the CM, it only does not unlatch the rear hatch when the CM is dark. When the CM is running then the door unlatches as normal. If the actuator has failed then the door never unlatches.

The rear hatch actuator has a very low failure rate so I wouldn't have any qualms about using a used one. Another interesting observation is that a 10 or 12-year-old part will look brand new. I guess it is pretty sealed up there in the back.