Yesterday on a hot Canberra day (~35 degrees C) my 2014 Clio RS 200 chucked a "Check auto gearbox" error.
It locked in a gear and I was stuck until I turned it off at the traffic lights and restarted it.
I have a little OBD2 HUD and I noticed that the voltages were odd. So today I also put in a cigarette lighter voltage monitor. I thought that perhaps the digitial voltage recorded from the ECU might not be the system voltage. In fact there is a constant 0.2 V offset between them, probably just A to D variation.
My voltages vary from about 11.8 to 15.1. Typically on a cold start they sit from about 13.8 V to 14.2 V and I'm happy. But then they start to jump all over the place. The battery seems to put out about 12.7 V but often I see 12 V or less when driving down the road. The same happens often at idle: the voltage drops steadily from maybe 13.5 V down to 12.1 V.
Such a wide range seems a bit crazy. Especially I don't want to be discharging the battery when idling in traffic! Or when driving down the road. I had a VW bus with a dead alternator and it didn't end well
And I'm pretty sure that in the colder weather the HUD showed 13.8 V to 14.1 V most of the time.
I've noticed that people often fix the "check auto gearbox" error with a new battery. But perhaps the culprit is really poor voltage control and the new battery just holds out better.
It locked in a gear and I was stuck until I turned it off at the traffic lights and restarted it.
I have a little OBD2 HUD and I noticed that the voltages were odd. So today I also put in a cigarette lighter voltage monitor. I thought that perhaps the digitial voltage recorded from the ECU might not be the system voltage. In fact there is a constant 0.2 V offset between them, probably just A to D variation.
My voltages vary from about 11.8 to 15.1. Typically on a cold start they sit from about 13.8 V to 14.2 V and I'm happy. But then they start to jump all over the place. The battery seems to put out about 12.7 V but often I see 12 V or less when driving down the road. The same happens often at idle: the voltage drops steadily from maybe 13.5 V down to 12.1 V.
Such a wide range seems a bit crazy. Especially I don't want to be discharging the battery when idling in traffic! Or when driving down the road. I had a VW bus with a dead alternator and it didn't end well
And I'm pretty sure that in the colder weather the HUD showed 13.8 V to 14.1 V most of the time.
I've noticed that people often fix the "check auto gearbox" error with a new battery. But perhaps the culprit is really poor voltage control and the new battery just holds out better.
