Common faults

This page is currently under development.


Audi : Common faults

ABS pump faliure. Fault code 01435 Brake pressure sensor 1 (G201).

 This is an internal fault in the ABS unit. Audi now supply a repair kit which allows the pump to be replaced without having to buy a completely new module/pump. This fault is also found on VW Golf, Caddy and Touran.

Audi A4 /A6 

Multitronic transmission ECU

This unit commonly fails. The fault causes the PRNDS light to flash and the gear box goes in to limp mode. usually starts off intermittent but gradually gets worse until it becomes a permanent fault. 

Audi TT, A3 DSG gearbox controller.

Same symptoms as described above on multitronic transmission ecu.

TT Instrument cluster fails

A common problem with Audi TTs. LCDs fail, gauges fail. Petrol gauge reads incorrectly. Cluster pulses.

BMW : Common faults

BMW 1 and 3 series. E87 , E90, E91 ABS DSC/ASC Pump problem.

Traction control light on. Fault reads hydraulic pressure sensor internal.
Like VAG , BMW are now doing a repair kit at reasonable price.

BMW M5 Thottle body 

Throttle body fails causing reduced power. The M5 has 2 of these fitted. found on years 2005-2009.

Citroen : Common faults

Citroen Saxo ECU fault

A very common fault on saxos. Cooling fan runs all the time and temp warning light flashes .Can also run erratic. Repair or replacement engine ECU required.

Citroen all makes. Airbag light on.

 Fault code relates to drivers airbag trigger 1 and 2. This is a break in the contact ribbon behind the steering wheel. A new or stalk / comms unit is required.

Citroen C2 airbag light on  (internal fault on VAN network) 

At first glance this fault appears to be an internal problem in the airbag module. However it is often caused by the steering functions ECU. rectify by replacing steering unit.

Fiat: Common faults

Fiat Punto Engine ECU Failure

engine misfire / no spark on 2 cylinders.
This is very common on 1.2 puntos . Misfire found on 2 cylinders causing poor running or non start. It essential to replace both coil packs when replacing ECU. 

Fiat Punto power steering failure

Very common on early Puntos but now becoming common on Grande Puntos. Power steering fails. We strongly advise replacing the whole column with the motor , ecu and torque converter. Many places now offer exchange units. 

Fiat Punto indicator problems

Indicators either don't work or stay on all the time. this is often caused by water ingress in to body module/fuse box.

Ford: Common Faults

Mondeo Turbo problems
Fault code P132A and P132B. This is a common fault found on ford Mondeo TDCI s that use an electronic actuator on the turbo. These fault codes relate directly to the actuator. Ford will only supply a complete turbo. 

Mondeo non start

Car fails to crank. Starter motor clicks. This is a common fault on high millage Mondeo diesels. The fault is caused by dust and debris from the dual mass flywheel and clutch as it breaks up and gets lodged in the starter. Replacing the starter motor might temporary fix the fault but fault will soon reoccur as the new starter becomes clogged.New clutch and flywheel is required along with a good clean out of the bell housing and starter.

Focus 98-05 Instrument cluster fault

Instrument cluster fault. speedo , rev counter and dials fail. warning lights flicker on and off. This is a cluster fault . ford now supply replacement refurbished clusters at a very reasonable price.

Focus 05- Present Tailgate opens when braking.

This fault is caused by water ingress to multi plug behind left hand trim panel in boot. High level brake light unit leaks water in and water run downs the loom in to multi plug in boot. 

Focus / Mondeo Misfire non start ECU fault 

Often runs on 2 cylinders or might not start at all. This is often down to engine ECU failure. We recommend replacing coil pack at same time as this part usually fails first and damages ECU.

Focus / Transmission problems

Fault codes in engine management  P0500 and U0101 and no communication with transmission module. Lights flash on dash and manual shift does not operate. This is cause by corroded wiring in engine bay. check the 3amp fuse in front fuse box. trace red / black wire from fuse box to transmission unit. Break is usually just before connector block on top of gear box

Jaguar: Common faults

X-Type  Turbo Actuator

This is a common fault on diesel X-Types . Causes the glow light to flash and restricted performance. same fault as Ford Mondeo . See above. 

S-Type Automatic: Non start  erratic gear change

Fault code in engine reads Park neutral position switch and loss off communication with Transmission ECU. fails to start , restricted performance and erratic gear change is experienced. This is not a fault with selector module but a fault in gearbox . Requires new Park position switch/transmission unit. Does require programming on IDS.

This page is constantly being updated.


Mercedes : Common faults

Sprinter ABS Fault.

This is a common fault on sprinters causing the abs light to illuminate. Fault code reads C1401 Return pump failure

A Class Poor running / cutting out

A very common fault on the A class. This is often caused by the Mass airflow meter . Fault codes often found are P0100 and codes relating to fuel trim. Many companies now repair these as a replacement unit is in excess of £1000 fitted from Mercedes due to having the ECU incorporated in to the Mass airflow meter. 

S Class and E Class dash back light failiure

This is an internal fault in dash which is repairable. Pixels on LCD also fail

S Class, E Class , CLK  partial or full loss of wipers

Wipers failing are a common problem , sometimes on just one speed. The switch on the column is often at fault and requires replacing. 

SL Class 

Central locking fails . This is caused by central locking pump failure. If pump operates OK check vacuum pipes for splits.

Nissan : Common faults

Micra K12 electric power steering failure

Usually fails intermittently and causes power steering light to illuminate. comes as replacement column complete with control unit and motor. 

Micra Throttle body

Poor idle , cutting out and poor acceleration. This is caused by throttle body on Micra's from 92 - 97. Fault is due to Mass airflow meter being incorporated in to throttle body.

Renault : Common faults

Megane Scenic instrument cluster failure

This is a common fault and Renault dealers in the UK are currently offering to replace the dash for around £100 . Instrument display usually starts to flicker then goes off completely.

Megane Scenic rear lights / electrics failure

 A common problem on the Megane Scenic range is electrical faults on electrics to the rear of the car. this can effect doors , lights and various other things. Remove the pocket under passenger seat . Under the floor there is a multi plug for the rear loom. Check for water ingress here as the plug is prone to corrosion.

Vauxhall / Opel

Combo / Astra 1.7 DTI  Non start or cuts out 

This is a very common problem and is caused by the EDU which is fitted down the back of the engine. These are not coded and can be replaced like for like. 

Corsa / Combo

Indicators stick on one side . This is caused by twin flasher relay which is mounted under relay cover under bonnet next to battery. Its easy to spot as its yellow and twice the size of a normal relay.

Zafira Rear central locking / electric window failure

Failure of any functions on the rear doors for example central locking, electric windows or speakers is often caused by wiring breaking in the door loom where it goes from the car to the door . disconnect the plug at the door side and pull back rubber boot to reveal damaged wiring and repair as necessary.