Code 26, Quad driver A
and 55 EGR solienoid 3
Any definitions, i dont have my scanner on me..

code 26 scares me since it says quad, I will let bill or somebody answer that

That might be related to the 55 i dont know.

but EGR one sounds like a bad EGR valve perhaps? have you tried the good ol clean and lubricate method?

Primary purpose of the Quad Drivers is to provide a ground for the devices they are assigned. This includes fault detection. It will set if:

1. Engine has been running for more than 5 seconds.
2. The PCM detects an improper voltage level on a circuit connected to the QDM.
3. The above condition is met for 5 seconds or longer.

Check the following components:

Canister purge solonoid
Temperature lamp (not likely)
Low speed fan relay
TCC apply
TCC PWM solonoid
Shift solonoid A or B.

In other words, your canister purge solonoid is disconnected or smoked, your temp lamp is disconnected or burnt out, your low speed fan relay is disconnected or smoked, or you have another shift problem with the trans.

(or the associated wiring)

EGR: I get one of the 3 EGR codes once or twice a year. The digital EGR (which lasted through 1993) responds very well to a little toothbrush TLC and some lube. It hasn't failed me yet.

^^^ yup and;


The quad driver is located inside the PCM. the Q/D consists of four separate electronic
switches used by the PVM to energize various solenoids and relays.

The PCM checks the condition of the Q/D switch out put and displays eather LOW
(switch is ON) or HIGH(switch is off)

Be in mind that this display is indicating the actual condition of the switch out put and
NOT the command given to the switch by the PCM.

Matt, I hate to tell you this, but the 26 code generally (most cases) ends up being a shift or TCC problem.

Trans is shifting phenomenally well still
Did a run with the scan tool, all values are perfect.
Cleaned out the EGR, its good to go now.
OD works and all, unlike last time were it threw the code at the last minute..
the QDM one has not come back all night.

While i scanned i recorded
103 IAT (heatsoaked to all hell)
6 Degrees of KR at WOT no matter what..
150 LT fuel trim
and Rich exhaust at WOT..
hmm..still stumbles a bit..

i forgot to mention the light came on when i locked up my binders at 45 mph on the highway due to traffic doing so ahead of me..
thats right when the SES came on.

That'* probably important...

Did you clear and drive to see if they came back?

The light shut itself off on my way home last night to get my scanner, I then deleted both codes, put on around 20 miles no SES light on at all..
Odd with the brake thing, but thats exactly when it happend.
Not tires locked up, but threshold forsure.

Try jumpimg on the binders again see what happens......