Toyota Granvia: At the Mercy of the Computer

About the worst car problems anyone can run into are the ones caused by electrical problems caused by faulty electronics. Long gone are the days of cars with simple electronics where most problems are typically mechanical where a workshop mechanic can easily fix. For almost a year now, my 1996 Toyota Granvia car suffered a problem that left me manually shifting an automatic transmission vehicle from L to D to get it moving. In the beginning it would only happen intermittently (the worse kind of trouble) and if you can relate to this problem, the transmission would not kick down to L when it should so the car pretty much stayed in D and vehicle would be too heavy to leave the line at a junction or traffic light—this isn’t only extremely annoying but potentially dangerous.

The fix. It wasn’t until this Christmas holiday when my dad decided to look at the ECU (electronic control unit), the computer that manages the entire operation of the vehicle and often has capacity to learn and adapt to driving patterns. It was discovered that one of the two condensers had leaked onto the printed board and inadvertently shorted the circuit that controls the transmission functions.

Don’t rule out the possibility of faulty electronics in a vehicle that has clocked several hundred thousand kilometers. It’s often difficult to narrow it down but when they start to leak like it makes troubleshooting a lot easier.

 

Update: 15 February 2011 | On the 5th Feb 2011, third day of the Lunar New Year celebration, the glow plug warning light came on and would not extinguish (normally disappears in a split second). Worried that the glow plugs might be over heating (worse case scenario) I made sure they weren’t glowing red risking breakage and imminent engine damage. It was only a few days later when the real problem reared it ugly head—the engine started to rev really high on start-up. Checked all fuses and relays to no avail until a close look at the ECU and my dad once again located the culprit.

The culprits—two faulty condensers—that triggered the high revving engine symptom.

Toyota Granvia 1996 ECU model made by Denso

Although there’s a wealth of information on the web, it seemed no one has encountered a problem like this or published a report of one that I could find. I decided to post this article as a contribution to the growing list of problems owners encounter, no matter how unique it may be!

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