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'''Will have to do free air calibration and upload vemslogs (obviously required for support). Related to Bosch Lambda sensor (LSU4.2 or LSU4.9 ?)''' '''All information required for support is simply missing: sensor placement, wiring connection, measurements, vemslogs of symptom; and vemscfg or log from old working setup for comparison. Even the sensor type is not specified''' * After #10267 was replaced with new ECU #15379, after '''some minutes''' you are using the car, and more quickly if running it hard, lambda sensor stops working, lambda gauge on VT goes to max lean 1.83 and CEL switches on. * Everything returns fine again for few minutes if you switch off and on the engine. ** most often related to failed sensor, or misconfigured. Eg. free air calibration was forgotten ** if sensor heating is a bit weaker (cannot reach target) for any reason, might need to up-adjust WBO2 heater abs limit (up to 255). * Is there a way, looking at the logs, to understand what's going wrong in lambda sensor/v3 ecu controller? * '''capture vemslogs''' during sensor [http://vems.hu/vt/help/v3/v3_wideband_settings.html free air calibration]. ** also during the "some minutes" the symptom shows up * Is it '''LSU4.2 or LSU4.9 sensor''' and configured accordingly ? ** What is sensor measured Rcal (Ohm) value ? ** Is the ECU configured for LSU4.9 ? *** If LSU4.9 sensor, see [https://shop.vems.hu/catalog/lsu49-wideband-sensor-p-193.html LSU4.9 pdf] *** for LSU4.9 is the 27k (or 27k4) nernst pullup installed inside ECU, or outside in the harness ? What '''DC voltage is measured across known and documented value (1k .. 10k) pulldown resistor between nernst and GND''' ? (with sensor disconnected, ECU on, but engine off) *** That measurement is important. New ECU-s are, by default made with this 27k nernst pullup to support LSU4.9 sensors. No side effects have been experienced with LSU4.2 (if otherwise configured properly) but need to know the details anyway. * '''upload the vemslogs''' (captured during calibration and "some minutes the symptom shows up"), annotate the most interesting time window of each log I may add that this happened after old VEMS ECU was replaced with new, and never happened in 2500 kms with the old board. '''Current fw is 1.2.38.''' * What was old fw ? 1.2.31 ? * Maybe related to some '''unintentional side effect of upgrade''' ? * important: upload '''old config and new config please''', so we can compare. ---- * '''Support for ecu serial #10267''' ** A customer's V3.6 ecu suddendly lost serial number, seems to be in a kind of limp mode (10° and 0.65 lambda at any load/rpm). ** VemsTune is now displaying that Serial is unknown-0. ---- Granting (by info sent in priv), Do you have ISP cable (Parport DSUB25 or USB-ISP ?) Will need to follow http://vems.hu/vt/help/v3/general/bootloader_upgrade.html If considering bootloader upgrade, (so that internal BOD can be disabled) highly recommended: '''PLEASE CHECK THAT v3/10267 has reset chip at the atmega128/pin20 reset''', eg * mcp121 or mcp131 (U26 position) * or mcp809 or max809 (U10 position)''' See GenBoard/VerThree/Schematic eg [http://www.vems.hu/files/genboardv3/v3.8/genboardv3.8_sch.pdf v3.8.pdf] '''----------------------------------------------------------------------------------''' * '''Support required for VEMS EGT amplifier''' Engine off, ambient sensor temp (~20C) * Tested Pin7 DVM output (1V/100°C) and getting 0.7 volts ** corresponding to 70C ** not 6 volts, roughly corresponding to Pin6 2.5 volts. * '''I'm getting 2.5 volts out of Pin6''' (0-5V output, 1V/233.3C) ** '''Thus getting 580°C instead of 20°C.''' Hint: The '''output is almost certainly connected to an input with pullup''' (possibly strong pullup). * '''Diagnostic: disconnect anything from output, and measure DC voltage with DVM''' (the DVM has 1 to 10MOhm input impedance). * '''Solution: make sure to connect pin6 output to an input without pullup resistor''' '''Sensor connection (seems good)''': EGT sensor is K type yellow-red wires: ** yellow = green (plus wire) to board GND ** red = white (minus wire) to the board cathode on corner
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