code 26

[paul.p]

code 26 is showing on freescan , but the car seems to be running fine ,any ideas?

[Advantage]

Have a look through this area (ECU/Freescan) of the Forum. Lots of conversations about this.

[eriks4]

Checking whether it is a Quad driver group A or quad driver group B error will narrow it down. But be careful since Freescan provides the wrong hints in terms of the possible causes.

Good luck,

ErikS4

[fesuvious]

Have you checked to see if your engine check light is working ok? A code 26 should throw up the light but you didn't say the light is on.....

A broken bulb (eng check) will throw a code 26. Also, code 26 will limit boost to .65 so the car should feel slower.

[paul.p]

thanks for the tips ,yes the engine check light is on and i couldn't tell about the drop in boost as its still a bit slippy

[fesuvious]

Okey pokey, next step, check all vacumn lines, including the elbow at the map sensor

[paul.p]

tried that but no luck is. the light takes minute to come on . cheers for the suggestion

[fesuvious]

Driving or idling?

If it is idling then it could be the IAC - idle air control - might be worth unplugging it (on side of the exit end of the chargecooler, above spark plugs) and cleaning out the connector.

Having said that the part itself is only @£20.

I presume you have used freescan to do a reset? (or had the battery disconnected @ 3hours) - Have you reset the IAC using freescan?

[eriks4]

Hi, I don't see how something IAC related would set a code 26. Did you already check whether it is the A or B circuit? With A the possible causes are:

Radiator fan relay

Wastegate solenoid

Canister purge solenoid

Check engine light

With B they are:

RPM relay

AC control relay

Engine overheat relay

Throttle jack solenoid

Secondary injectors

Good luck,

Erik

[Sparky]

Very often a dodgy relay, still functioning but incorrect resistance. I'd be pulling all these first.

[paul.p]

hi thanks for the tips, i will try all of them as soon as poss oh , thankyou for taking the effort to help Paul

[mr.oogieboogie]

Hello everyone I have had code 26 appear showing quad driver and waste gate and engine check light also showing code 26b possible secondary injector can someone point me in the direction of the relay engine check light appears at idle also the low level coolent light is on but level is fine any info would be great

Edited March 13, 2011 by mr.oogieboogie

[eriks4]

Peter,

You mention it is the Quad driver B circuit. If you have used Freescan to determine this, be aware that the identification of QDM B is correct, but due to an error in the Freescan code the hints suggested as a possible cause are wrong. For the correct mapping of QDM A and QDM B to the possible causes see either the Lotus manual or my post in this topic from December 15.

Good luck,

Erik

[mr.oogieboogie]

hello erik, yes i have the lotus maunal, but im not too good with the wiring diagrams, is there a relay/s to check and and if so any idea where they are?

[eriks4]

hello erik, yes i have the lotus maunal, but im not too good with the wiring diagrams, is there a relay/s to check and and if so any idea where they are?

For QDM B there are several relais to check. The location depends on whether you have an S4 with the older wiring harness or the revised wiring harness. In the latter case the relais have been move to a small block box near the rear right hand wheel arch (the included picture shows both options).

in the revised wiring harness relais box (picture), B is the RPM relais, C the throttle jack changeover, G the secondary injector resistor and I the AC relais. Failure of any one of these will set the QDM B.

In the revised wring harness car there is no engine overheat relais, the light is driven directly by the ECU (if I remember correctly)

In the following figure you can see which relais will cause a QDM A fault and which ones cause a QDM B fault.

One way to test the relais is to use the 'e' option in Espritmon (see the manual). You can control all relais separately (switch them on and off). If the relais is broken, you will not here it click, otherwise you will. If it is an intermittent fault it will be harder to find. In this way you can also test the engine overheat light in a revised wiring harness S4

Good luck,

Erik

[mr.oogieboogie]

hello erik, thank you for that. it looks like the float in the headder tank is triggering the check light for low coolent and the engine check light. as with the sensor disconnected no low level light or engine check light. i am going to try to free the float up and see what happens, if i cant i will replace the sensor. thanks to sailorbob who called in , good to see you again derek

i will also run the esprit mon and see if it shows any issues.

all the best

[dodge1979]

Was this the cause of your code 26,?