Limp mode

[Ca11um43]

Shortly after I left for work this morning, my car went in to limp mode and the glow plug light was flashing constantly...Once I got to work, I scanned it and it came up with 2 engine faults. The first one was P0088 (fuel rail/system pressure too high), and the second one was P0016 (crankshaft position - camshaft position: Correlation Bank 1 Sensor A). I cleared the codes and now the car is back to normal, so it's definitely something electrical. Somebody I know says that the crankshaft sensor needs to be replaced, but it also mentions the camshaft sensor so I'm not sure. If it is the crankshaft sensor at fault, then how hard is it to replace? I know the camshaft one is a pain (looks like the timing belt and everything has to come off). The car is a 2009 Audi A3, with the 2.0 TDI (CR) engine. TIA

Edited November 24, 2022 by Ca11um43

[Steve Q]

I'd definitely go with changing the sensors. But see how long you go without the issue coming back. 

[Ca11um43]

22 minutes ago, Steve Q said:

I'd definitely go with changing the sensors. But see how long you go without the issue coming back. 

Any ideas how easy it is to change the crankshaft sensor? And what brand to go with? From what I've seen, a lot of things including the timing belt have to be removed to replace the camshaft one 😢 So that will have to be a last resort. I'm happy to change the crankshaft one first though, if it's easy enough to do. Then go from there.

 

Not long after buying the car, I did have an issue where it said the battery voltage was too low on the dash, the car wouldn't start (it would fire up and die straight away), and I had a fault code for the crankshaft sensor. All of this started at the same time. I can't remember what the fault code was, but I'm pretty sure it was different to the one I'm getting now. All I did was change the battery, and it has been fine since. Until today. 

Edited November 24, 2022 by Ca11um43

[cliffcoggin]

14 hours ago, Ca11um43 said:

 All I did was change the battery, and it has been fine since. Until today. 

Was that a new battery you fitted or a secondhand battery? Dodgy batteries are known to disturb the cars electronics leading to apparently unrelated warnings, false error messages, and symptoms such as limp mode.

[Ca11um43]

20 minutes ago, cliffcoggin said:

Was that a new battery you fitted or a secondhand battery? Dodgy batteries are known to disturb the cars electronics leading to apparently unrelated warnings, false error messages, and symptoms such as limp mode.

It was a second hand battery...However it is only a couple of months old (I originally bought it for my previous car). According to all my battery testers, the battery which came on the car is absolutely fine, and it's now being used on a different car with no issues 🤷‍♂️ I also tested it while it was still on the Audi, and both voltage readings with the engine on and off were fine. But for whatever reason the car kept saying it was low, and then refused to stay running. 

 

The battery was disconnected for about a week before that first issue started, but like I said, I changed the battery and it has been absolutely fine for the past few weeks. In fact the car is fine again now (after clearing the codes yesterday). So far it has only gone in to limp mode once, but I imagine that it will happen again at some point. 

Edited November 25, 2022 by Ca11um43

[cliffcoggin]

A simple voltage test will not always reveal internal battery faults, nor will such faults necessarily interfere when used in another vehicle. If the problem occurs again I recommend you fit a new battery before spending a lot of time and money on sensors.