Won't Start and Multiple Electrical Failures
Failure to start could be any of the following:
A low battery can cause failure to start as the electronics require at least 10 volts to work properly.
However if turning the ignition key produces no action at all then
- the battery condition is important on all modern cars. Ensure the battery is up to scratch; they can fail suddenly.
- the brake light switch may be at fault as it is part of the ignition circuit on automatics - it is up underneath the passenger (RHD cars) glove-box
- some have also found that the starter motor fails when hot but can be OK after it has cooled down.
- an automatic gear fault can lead to a failure to start as the two ECU's (gearbox and engine) talk to each other.
- if the ignition key has been damaged or opened up for any reason then make sure the transponder is still present
- The Security Module can get upset if the battery is dabbed on/off; doors repeatedly opened by hand (as opposed to normal electrical operation) - in which case try a battery reset
- Dead car after battery has run flat.
The car may have entered "economy mode" if for example, you were cleaning it with the doors open and radio on and run the battery down to trigger the warning. Normally this isn't a problem and the car starts normally, but apparently Peugeots can occasionally be a pig to get back out of this mode.
The trick is to run a thick wire from the battery positive terminal directly to the starter motor and force the car to turn over with the ignition turned on. This makes the car start and come out of Economy Mode.
Once started leave the car running for half hour or so to let the battery charge up and for everything to reset itself.
Multiple Simultaneous Failures
- Often caused by an old or weak battery; especially on the autos which require a good quality battery in good order
- Weak or failing alternator not charging battery properly
- Can be caused by poor earth strap from battery negative to chassis and/or engine.
- Neil Gibson had an unusual problem: Doors not working, power steering off and gear box failure warning light on. ABS light on intermittently. Sounds like a car destined for the breakers but the problems are all related. These days it is necessary to look at more than just the obvious as virtually every component relies on data supplied by other often seemingly unconnected units. What connects the doors, steering and transmission? The ABS module! They all rely on speed data to operate properly. Don't forget the doors are programmed to open only below 3 mph. No speed reading and the ecu says NO. After checking the fault codes and opening the ABS ecu there was clear damage to the circuit board. Whoever decided to put the ABS module low down and in front of the road wheel wants shooting. I bought a secondhand ABS Pump for £35. Be careful to match the serial numbers AND be careful to ensure that it comes from an identical vehicle. It is programmed for engine type, transmission type and wheel size. If it's not you will need the Peugeot planet software to configure it otherwise it's plug and play. Or should be! The replacement unit showed fault codes for both rear wheel sensors. One sensor you can believe but two is more likely a faulty ABS ecu So on to unit #3. Found fitted and all the other problems disappeared. The moral of the story is think outside the box !
- A faulty coolant temperature sensor can confuse a smart charging system into shutting down an alternator leading to unnecessary and repeated replacement.
- For the second time in a while Neil Gibson has come across a Citroen C3 with water in the ECU connectors. So this probably applies to the 1007. Symptoms are misfire; odd warning lights; cut out or non start. Unplug the engine ecu. If connectors are wet then taste them. Antifreeze? Neil did get a workshop manager to admit that coolant temperature sensors are known to leak, forcing coolant through the core of the sensor wire and ultimately damaging the ECU.