Multiple error codes

[moundtown]

The Service Engine Soon light in my 1995 Jimmy came on. I had it checked with a code reader and it came up with the four error codes P0135, P0340, P0141, and P1406. It was suggested to me that it wasn't likely that four system components failed at once and that a vacuum leak was most likely causing all the errors. I did find a good sized hole on a PCV valve hose and replaced it. After disconnecting and reconnecting the negative battery terminal the Service Engine light went out only to light up again after a few minutes of driving. What else should I be checking for?

[Airjer_]

What codes came back?

[moundtown]

Originally Posted by Airjer_

What codes came back?

All of them.

[Airjer_]

Chevy guys correct me if I'm wrong but if this is OBDII than disconnecting the battery may turn off the light but it won't clear the codes. I think the better option would be to clear the codes with a scan tool and then see what codes come back.

Two codes are heater circuit malfunctions on the bank one O2's, One is a cam sensor circuit issue, and one is ang EGR issue. Hard to imagine that they are all linked somehow so I think clearing the codes with a scan tool and then seeing what comes back would be the next step.

[moundtown]

Originally Posted by Airjer_

Chevy guys correct me if I'm wrong but if this is OBDII than disconnecting the battery may turn off the light but it won't clear the codes. I think the better option would be to clear the codes with a scan tool and then see what codes come back.

Two codes are heater circuit malfunctions on the bank one O2's, One is a cam sensor circuit issue, and one is ang EGR issue. Hard to imagine that they are all linked somehow so I think clearing the codes with a scan tool and then seeing what comes back would be the next step.

Well, I went and had the error codes cleared and before I had driven a mile the SES light was lit again. Went back and had the error codes checked and the same four showed up.

[old_master]

Always diagnose DTC's (Diagnostic Trouble Codes) starting with the first code. After the repair, clear all DTC's and road test the vehicle. If any DTC's are re-set, again start your diagnosis with the first DTC. The ONLY way to clear DTC's on an OBDII equipped vehicle is with a scan tool.

Your P0135 indicates a heater problem with the oxygen sensor circuit on the driver side bank closest to the exhaust manifold. Disconnect the sensor, turn the ignition switch to the RUN position and check for power and ground in the vehicle harness connector. If you have power and ground, the oxygen sensor needs replacement.

[moundtown]

Thank you to everyone who replied. An employee at a local auto parts store suggested that I check all the fuses. I found that a 20 amp fuse in the Engine 1 slot was blown. After replacing it the SES light went out and has not come back on. It turns out that the Engine 1 fuse powers the sensors that were creating the errors.