QuestionQUESTION: I have a caddy in which I replaced the fuel pump and the fuel filter. It drove well for about a month, then one day it wouldn't start. Replaced the fuel filter again, but still nothing. On the self diagnostics I received a 26, 27, and 38. Can you give any help at all on this problem? I know the fuel pump works, and I also know the injectors are getting fuel. I tried with starter fluid, and it did start, but cut off immediately after. Thank you so much for any help you can give.
ANSWER: When the codes display are you only getting:
..E26 or are you also getting .E.E26
..E27 or are you also getting .E.E27
..E38 or are you also getting .E.E38
What you need to do is CLEAR (erase) ALL the codes via the climate control panel:
1. Re-enter diagnostics and after the codes display you will see .7.0
2. Simultaneously push and hold the OFF and HI buttons until you see E.0.0 and then release the buttons.
3. Start the car and see if you get E and or EE codes and let me know.
26 = Shorted throttle switch on the front of the IDLE SPEED CONTROL MOTOR (ISC) OR someone has tried to manually adjust the idle speed by turning the idle screw.
27 = Open throttle switch circuit.
38 = Opem MAT (Manifold Air Temp Sensor) located on top of the engine in the intake manifold.
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QUESTION: I'm getting only the numerical error codes, nothing is preceded by an E or an E.E I will clear the codes in the morning as you suggested in the morning, but can you give me any idea what the problem may be? Do you need any more information? Thanks.
AnswerSince the MAT (Manifold Air Temp) sensor is showing an open circuit. I would test the MAT sensor resistance and the coolant temp sensor resistance to see if they are approximately the same resistance after the vehicle has set overnight and the engine is cold.
I would also check the MAT sensor wiring at the sensor for corrosion or just simply replace it and CLEAR (erase) all the codes from the computer and see if any return.
