Buddy_M Posted December 10, 2012 Share Posted December 10, 2012 OK hoping someone can provide some help on this one as I'm about at my end on it. 2005 6.0 brought in on the hook with no throttle pedal response, codes P2104, 2122, 2127, 2132, 0107, and 0237, all related to APPS, BARO, and MAP sensor low. Disconnected all 3 sensors that feed off the circuit and had no vref power going to any of those sensors. Backprobed at PCM pins 29 and 45 and no vref there either. Checked resistance (and load tested with my 4656 bulb), short to ground/power thru all VREF circuits to the APPS, BARO, and MAP and all good there. Swapped in a known good PCM and still no change, so checked powers and grounds to PCM just in case and no issues there. Reflashed PCM as well to no change in the problem. Anyone got some helpful insight, or perhaps I may have missed something here? Quote Link to comment Share on other sites More sharing options...
Mikill Posted December 11, 2012 Share Posted December 11, 2012 check ebp sensor. I have seen alot of those short out vref. Quote Link to comment Share on other sites More sharing options...
joshbuys Posted December 11, 2012 Share Posted December 11, 2012 OK hoping someone can provide some help on this one as I'm about at my end on it. 2005 6.0 brought in on the hook with no throttle pedal response, codes P2104, 2122, 2127, 2132, 0107, and 0237, all related to APPS, BARO, and MAP sensor low. Disconnected all 3 sensors that feed off the circuit and had no vref power going to any of those sensors. Backprobed at PCM pins 29 and 45 and no vref there either. Checked resistance (and load tested with my 4656 bulb), short to ground/power thru all VREF circuits to the APPS, BARO, and MAP and all good there. Swapped in a known good PCM and still no change, so checked powers and grounds to PCM just in case and no issues there. Reflashed PCM as well to no change in the problem. Anyone got some helpful insight, or perhaps I may have missed something here? There are a number of items on the VREF circuit - Baro, EBP, EGR, ICP, MAF, Fan Clutch,etc - I've seen A LOT of fan wiring cut causing a died/no start, as well as EBP's chaffed. Quote Link to comment Share on other sites More sharing options...
Aaron Posted December 11, 2012 Share Posted December 11, 2012 Yah, the whole VREF circuit is suspect at this point. EBP would be the first place I'd head at this point. Quote Link to comment Share on other sites More sharing options...
Buddy_M Posted December 11, 2012 Author Share Posted December 11, 2012 Unplugged EBP and vref came right back up. I don't think I was expecting the engine sensors to have an effect on these other sensors since they used a different connector and pins on PCM. That and I trusted the IDS too much as the vref read 5v instead of taking a few extra seconds and measuring vref underhood at the engine sensors also. Thought that the PCM had a couple different vref outputs for various circuits.. apparently not, so something for me to remember for future if this happens again. Quote Link to comment Share on other sites More sharing options...
Aaron Posted December 12, 2012 Share Posted December 12, 2012 I think they're all on the same 5v bus even though they're on different pins/connectors in the PCM. Glad you got 'er fixed. Those can make you pull your damn hair out. Quote Link to comment Share on other sites More sharing options...
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