code 26?

[danny tattersall]

Hi there guys, anybody any idea what code 26 is? I got a check engine light and ran free-scan to read the fault code. Came up as follows:

26 - Quad driver (QDM) circuits
26 - TIP some relay (probably) or secondary injector is open - circuit
26 - B A/C clutch,EGR, CHk light, fan, wastegate or canister relay.

Seems like I have a lot of checking to do if somebody has not already had this problem and can give me an idea what cured it. Thank you in anticipation!

[JohnWatkins]

Hi Danny,

IIRC code 26 is the quad driver circuit. It represents 9 possible faults. If it is set the check engine light will come on and the ECU will shut down the boost for safety:

- RPM relay
- Radiator realay
- A/C control relay
- engine overheat relay
- solenoid relay (throttle jack)
- wastegate solenoid
- canister purge solenoid
- check engine light bulb
- secondary injector circuit

one of these is either broken, disconnected, short cut, whatever ....

For me it was the check engine light bulb which should come on & stay on until you start the engine .

Cheers,

John W
'95 S4s

[danny tattersall]

John, thanks for the help. I can safely say that it is not the check engine bulb as that is what alerted me to the fault in the first place! Oh well, 8 more to go eh? It was raining very heavily at the weekend when I was messing around with freescan etc and there are quite a few relays and electrical connections near the ALDL connector. Maybe they got wet. I will check them out next weekend when I get home. Thanks again.

[Ye Olde Esprit]

I have the exact same fault reported on my SE right now.

Have not been able to trace it except I suspect it is a faulty O2 sensor, but I need another to confirm it, or go to a garage.

Nicholas

[JohnWatkins]

Code 13 is the O2 sensor

Cheers,

John W
'95 S4s

[okc-esprit]

On my '90 SE this code turned out to be the secondary injector circuit. Only the combined efforts of GM and Lotus could put so many possible problems under a single code.

[danny tattersall]

My sentiments entirely. What a ridiculous idea to combine 9 possible faults onto one code! Narrows it down - NOT! I will just about have to check every part of the fuel system electronics. Can you remember exactly what part of the secondary injector system it was? It is just that if I can not solve it myself then I am worried that it will cost a fortune to have somebody else look through the whole system.

[okc-esprit]

I believe there was a short in the secondary circuit but I had long given up on the problem and the mechanic traced the short. I would suggest looking at points where the wiring passes through body panels or might rub against the engine etc. Apparently, there was some crimping at these locations. Since I had the work done at the standard service time, it wasn't too bad. Good luck.

[lotusman]

I had a Code 26 on my '89 non-SE for nearly 6 years. Had taken to the shop for a Tech 1 check. They got a B set of failures, but as they said, "How is it running." My answer was, "great" have boost, 150 mph and great mileage. They said, "don't worry". The important thing with Code 26, is what other symptoms do you have? My Code 26 went away when I replaced my chip with a Number 15. My radiator fans had came on whenever I turned the ignition, ODD. That meant the chip is fryed. But I also had the fuel pump relay go out( I jumped it for nearly two years) Even replacing the ECM(using the old chip) did not stop the Code 26. So, What year do you own and what other things are fishy?

You will need the EMG Section manual to do any parts checks. P. S. Even Freescan would not tell me my chip was dead.

Lotusman
'89 non-SE

[danny tattersall]

Lotusman, my car is a 1993 SE Highwing. Nothing else is fishy on the car. Everything was working fine and this problem only became apparent when I changed to the High Torque #3 chip. I do not know whether it could be down to my dodgy soldering but I presume that the checksum for the ECU software would be incorrect if there is a pin not connected properly? Can anybody comment before I start taking it out abd checking?

[roadburner]

Hi,i got fault 26 even on my 92`SE for 3 years.The problem starts after one week of owning that car.
I went to the Lotus shop and we read the faults out.
Code 26-Quad driver!But the mechanic doesn`t know what he das to do.
After these 3 years i`ve changed the Ecm because i got a problem with the Spark timing circuit(got misfire under acceleration).I also installed a new Chip(S4sMk5).And look there`s no more any electronic problem.

[danny tattersall]

Roadburner was it the new ecu that fixed the problem or the chip? Curious because I have a S4S mk 5 chip that I can try.

[roadburner]

Hi,
i mean it`s the ECU.But it`s a very cheap GM part.

[lotusman]

There is a great book entitled, "The Rational Manager". Its single philosophy is, "No change, no Problem". I have to think that unless you have been soldering ICs all your life that more than likely that is the problem. I had Marcus solder in the new chip holder to my Memcal for my new chip. Perhaps starting over is recommended. As most will tell you, bad connections to the ECM is usually the cause of check engine lights. Call sanj or marcus about getting a new chip holder soldered into the Memcal.

Lotusman
'89 non-SE

[Ye Olde Esprit]

I have noticed that on my Code 26 issue, the boost guage doesn't show a pressure rise anymore with increasing RPMs - the needle wobbles a little in the 0 position. It used to rise before, I'm sure, so the guage isn't faulty.

Could this 'symptom' be related to anything to do with Code 26?

Nicholas (MY92 SE HW)

[d didit]

Hi Danny,

Thought I'd post it here so that others can check. The resistor has three tangs. The middle is not used so the resistance is measure between the outermost tangs. I have 3.4 ohms. Check to see that you have the same or close to it. If not, purchase the resistor from JAE.

Cheers,
Dindo 95 S4

[danny tattersall]

Thanks for the info regarding the resistor value. Mine does not have any resistance at all - straight connection. Weird thing though isn' t it? It obviously serves a purpose so I think mine needs replacing. Thanks again!