OK, I had another thread about blocking off the EGR system in my Camaro (sig). The light is steady on all the time now, and here are the codes its pulling.

Engine codes
P1380
135 - o2 heater circuit
300 - random misfire
405 - EGR sensor "A" signal

ABS codes
56 - rear wheel speed sensor
110 - pump motor circuit malfunction

I'm not too concerned with the ABS codes at the immediate, the cars gears were changed and the speedo needs to be re calibrated, so I'm pretty sure that will clear that issue once I do that.

The engine codes, I'm still kinda lost on. I'm told that if I clear up the EGR thing it may clear the other two codes.

 

P0135 = B1S1 heated O2 sensor heater circuit.

The PCM sees the O2 sensor is taking longer than it should to warm up and start working. Hard to see how this would be related to the EGR valve, since EGR is not used at cold start, nor ar idle.

P0405 = EGR valve position sensor circuit low voltage.

The PCM is seeing less than 0.14V on the sensor postion feedback signal. Are you saying you deleted your EGR valve? That would explain it.

P0300 = engine misfire detected.

The CKP sensor is indicating misfires. Generally not caused by deleting the EGR valve, unless you haven't deleted it correctly. Use an "enhanced parameters" scanner and it will tell you which cylinders are misfiring. Might point you in the direction of the problem.

The GM online OBD-II code list for the 99 F-Body does not list P1380 as an engine or tranny code. I did find a generic list that indicates:

P1380 = EBTCM DTC Detected-Rough Data Unusable

That would have something to do with the ABS/TCS control module, possible related to your other ABS problems.

 

Thanks. I haven't deleted the EGR system, I was considering it depending on what it was gonna take to fix this problem. Everything is still there. If I clear up the 405 code, would that clear up the others?

Also, since the speedo is not calibrated correctly, would that affect the downshifting of the tranny? Or would that more likely be the converter?

 

Here's what my book says about the P1380: Engine misfire is detected (P0300), the PCM detected that an ABS fault existed preventing the PCM from receiving EBTCM Rough Road Data.

I think this is the first time I've seen the P1380 code mentioned on this board. Someone else will have to translate what that means.

 

OK... makes sense. This is what I ****THINK**** it means:

The CKP signal is used to detect misfires. The PCM looks at the signal and compares it to the tiny crank speed deviations it expects to see as each cylinder fires, compresses, etc. If you are on a rough road, the G's generated by the harsh bumps can alter the crank speed variations and hence the CKP signal. Appears when the ABS/TCS system detects a "rough road" it sends a signal to the PCM telling it to ignore the CKP "apparent" misfires. If a wheel sensor is bad, the ABS/TCS computer can't send the "rough road" data. So its just making you aware of the fact that the "misfires" may not be misfires, but could be crank rotational speed variations due to a "rough road". Its quite likely you have misfires.

In any case, the code for the EGR is from the position sensor. Either the position sensor on the EGR valve pintle is faulty, the EGR pintle is faulty and not moving to where it is supposed to be, or there is a wiring problem related to the pintle position sensor. Hard to see how "clearing' this code would get rid of the O2 heater code, the misfire code, or have any relationship at all to the wheel sensor problem. Maybe a far stretch that if the PCM is thinking the EGR valve it open, when its not, its not supplying enough fuel, or vice-a-versa.

 

OK well I don't drive on any rough roads, but there is some tire wear out back that is causing a hum at freeway speeds, (becomes apparent at about 55), and a slight vibration, could it be interpreting this as a "rough road"? I also need new rotors up front.

Otherwise, where would you guys start at to fix this? I can put it in the shop in the next day or two to have some diagnostics done to pinpoint some problems. I guess that would be the way to go, and then start from there. I know it'll run me about $150ish, so I'm not really anxious about that. Any more suggestions?

 

Borrow an EGR valve from someone, install it in place of yours and see if P0405 goes away. If you have a friend, the cost is "0".

 

Well the thing about that is that a friend had one laying around (he used to part out cars), so we switched it on there, and the code went away for about 70 miles or so, then it became intermittent, now its constant. The "ABS INOP" light never went off.

This one is gonna be frustrating, I already know it.

 

The ordinary consumer grade scan tools will not read ABS codes, so that most likely means a trip to someplace where they have the correct scan tool to pull that code. If you've messed with the plug wires, it's possible one is to close to an ABS sensor, and that will cause the ABS light to come on. Heck, I'd be checking the plug wires anyway, as it only takes one bad one to set the P0300 code.

 

Ya a buddy of mine has a Snap On scanner. Im plannin on getting a new EGR valve tomorrow to see what happens.

 

Update:

So I replaced the EGR valave last week, bought it new. Cleared the codes, cars is running way better all around. Even cleared up a tranny issue I was having .

Anyway the light came back on and I pulled the code, just the o2 sensor now, Ill get to that sometimes this week.

I think tomorrow Ill pull the rear wheels and clean the speed sensors or rings or whatever they are and see what that does for me. Any other suggestions?