Hi, I've been trying to pinpoint the root cause of the codes I've been receiving. The check engine light is on and I'm getting the following codes:
P1132 Lack of Upstream Heated Oxygen Sensor Switch Bank 1
P0141 O2 Heater Circuit ( Bank 1 : Sensor 1 )
P0155 O2 Heater Circuit ( Bank 2 : Sensor 1 )
P0135 O2 Heater Circuit ( Bank 1 : Sensor 1 )
P1152 Lack of Upstream Heated Oxygen Sensor Switch Sensor Indicates Rich Bank 2
I had an O2 sensor go bad on me a couple years ago, replaced it and was groovy. Now I'm showing 2 are bad. Including the one I previously changed? I'm a little skeptical it's the sensors this time.
+ Visual inspection of wires and terminals looked good.
+ The fuse is good. (15amp under the hood).
+ Voltage is getting to the sensors, Pin 1 & 2. I'm not sure what I would be checking for on pins 3 & 4, they lead right back to the PCM.
+ The MAF, looked super clean.
+ Recently did a service with clean air filter/oil, fuel filter, plugs & wires
+ Throttle body is clean
+ Did not find a vacuum leak (with a butane test hoping I wouldn't burst into flames)
--- I did find a couple small hoses from the EGR system that were suspect and changed them out.
+ Other than that, the EGR system was clean and functioned properly.
+ Checked the fuel pressure (was on target according to chiltons)
--- Not a fan of chiltons, are there better alternatives? Haynes seems a little better. Did I just answer my question or is there an even better one?
Though I did have voltage to the O2 sensors, this fancy live data scan tool says the voltage amplitude to HO2S11 & HO2S21 was 0.00. The switchpoint for both upstream and downstream tested OK at.45 &.50 respectively.
Also, I was seeing FUELSYS1 - Open Loop Fault, then it stopped that and was switching from OL to CL with no fault.
This is from the live data sitting at idle.
SHRTFT1(%) = -100.00
SHRTFT2(%) = -100.00
LONGFT1(%) = -100.00
LONGFT2(%) = -100.00
O2B1S1 = 0.000 v
SHRTFTB1S1(%) = -100.00
O2B1S2 = 0.000 v
SHRTFTB1S2(%) = -100.00
O2B2S1 = 0.000 v
SHRTFTB2S1(%) = -100.00
Here is the Freeze Frame data:
FUELSYS1 = OL-Fault
LOAD_PCT = 47.5
ECT = 188 f
SHRTFT1 = 3.9
LONGFT1 = 0.0
SHRTFT2 = 3.9
LONGFT2 = 0.0
RPM = 1838
VSS = 40mph
I'm no doctor, but the only idea I have left is that it is the PCM's fault and I need to replace it. But I would not be offended when you point out my ignorance and point out the real offender.
Any help is much appreciated.
Tuesday, June 17th, 2014 AT 4:58 AM