KIERS GARAGE

Home / Fault codes for flippers

Fault codes · from my own jobs

Fault codes for flippers: what they mean for your max bid.

A warning light on an auction or Marketplace car isn't a reason to walk away on its own. What matters is what's behind it, and how big that job is. These are real cars I've had my scanner and meter on. Use them to price the worst case into your max bid.

A long list of codes after a car has sat

Car
2017 Nissan Qashqai 1.2 DIG-T.
What it was
37 stored codes, most of them left by a flat battery after the car sat for about a year. One real fault in there: a misfire on cylinder 4 (its counter on 1,440, the others on 2, 0 and 8).
For your bid
Don't panic at the number of codes on a car that's sat, as a flat battery leaves a lot of them. Look for the one that stands out, like that misfire counter, and price that in. Once it's yours, save the full list, clear them, give it a proper drive and scan again: some faults only come back after a drive.

The full job: Qashqai engine light with P0597: how I found the faulty thermostat

P0597, thermostat heater circuit (Nissan 1.2 DIG-T)

What it was
The heater element inside the thermostat. It read 220 ohms against 15.6 on a new one. The wiring and the feed were fine.
What the job involved
The intake manifold off to reach the thermostat, then a coolant bleed from both bleed screws.
For your bid
The part isn't the job, the access is. Price in the manifold-off labour, and test the wiring first so you know it's the thermostat.

The full job: Qashqai engine light with P0597: how I found the faulty thermostat

P2009, intake runner control circuit low (Mazda 5)

What it was
Both solenoids on the intake runner unit read open circuit, so both were dead.
What the job involved
Two new solenoids, codes cleared, nothing back on a scan with the engine off or running.
For your bid
A meter test tells you if it's the solenoids before you price anything bigger. On the same car the oil was on the minimum mark, the coolant low with bits in it and the power steering fluid black: look under the bonnet too.

The full job: Mazda 5 engine light with P2009: both intake runner solenoids dead

U2101, control module configuration not compatible (Ford Transit)

What it was
A live fault that keeps the engine light on. On the same van the air con didn't work even after a new compressor, switch and regas: live data showed 0 V and 0 psi on the air con pressure, and the plug was wired for a switch while the engine computer looked for a sensor.
What it needs
An air con check with gauges first, then a Ford dealer or an auto electrician with Ford software to check the engine computer against the VIN and set it up.
For your bid
A code that clearing won't fix, and a job you can't do on the drive. Price a specialist in, or walk.

The full job: Ford Transit U2101 and air con that won't work: when the engine computer's set-up is the problem

Airbag light, airbag unit not talking (Citroen C3)

What it was
The passenger airbag had already gone off, the dash cover was torn, and the airbag unit wouldn't respond to the scanner. Both yellow plugs under the seats were unplugged.
What it needs
A full airbag system inspection and repair: the other airbags, the seatbelt pretensioners and the sensors. An airbag light on is an MOT fail.
For your bid
Look at the dash and under the seats before you bid. If the unit won't talk, it's a big job: walk away unless it's priced in.

The full job: Citroen C3 airbag light: what the scan found

Losing coolant, block test turns yellow-green (Vauxhall Mokka 1.4 Turbo)

What it was
The thermostat, some hoses and the tank had already been changed and it still lost coolant. The block test went from blue to yellow-green (a sign of combustion gas in the coolant), the coolant frothed and overflowed with the engine running, and the exhaust smelt sweet. The oil was clean.
What it needs
A leak-down test to confirm, then the head gasket, with the thermostat housing seal, hose and belt done at the same time.
For your bid
New cooling parts in the history don't mean it's fixed. A block test takes minutes. Treat yellow-green as a head gasket until proven otherwise.

The full job: Vauxhall Mokka 1.4 Turbo losing coolant: how I tested for a head gasket

Red oil light, cam positions not matching (Ford Fiesta 1.0 EcoBoost)

What it was
On live data the camshaft's actual and desired positions didn't match. The diagnosis: a blocked oil pickup in the sump, or a sticking cam phaser.
The repair
The owner did the fix himself.
For your bid
A red oil light means stop. On this engine the timing belt and the oil pump belt run in the oil, and a blocked pickup often means one of them is breaking up. Price the belts, the sump off and the pickup cleaned at the least, and a damaged engine as your worst case.

The full job: Timing belt in the oil: what to check on a PureTech, EcoBoost or EcoBlue

The full sheet has two more: a gearbox speed sensor code that brought power steering and ABS codes with it on a Honda CR-V, and clutch slip codes on a BMW 118i. They are for Car Flip Academy members.

These are my own jobs, one car each, not a price list. If you want me to look at a car before you buy it, my used car checks start at £95 round Hemel.

Book a used car check

Not sure what to bid? Bring the car to the Thursday live

In Car Flip Academy I show beginners how to flip their first car: what to buy, what to check and the most to bid. Every Thursday at 7pm UK time, members bring listings and I go through them live: the likely repairs, what the car will sell for and the most I'd pay.

Start the 7-day free trial Free max bid calculator

Buying a used car? Run the reg through my £7 history check first.