Hi there everyone, I want to turn to your knowledge about this issue I'm having, story goes this is a South American (Colombian made by SOFASA) 2003 FZJ75 cab and chassis, turned into an ambulance, the ambulance company did a not so good job on the wiring harness, they didn't install a separate fuse box for the needs of the ambulance compartment and at some point one of the taillight cables overheated and caused a short (from what I can see inspecting the harness). Anyway, I cut all those cables because I'm installing a style side tray; I inspected the harness in the engine bay and dashboard, repaired the shorted cable, fuses, etc., tried to start the engine but no dice, everything was completely dead, so I went and started the engine forcing fuel through the intake manifold, all the lamps in the dashboard lighted on and that was it at that time, then I checked the fuel delivery harness, fuel pump, main relay, circuit opening relay, fuel pump relay and everything works fine, replaced the fuel pump connector because it was in bad shape but nothing unusual apart from that so I started to suspect the problem was somewhere else, so I decided to check the condition of the ECU and as I shacked free from the connectors something rattled in the inside... When I opened found this:
The transistor's circuit overheated and fell off from the board, tested it and still works correctly, measured the resistors and the show very low values, not sure if they are OK or damaged, values were in the order of 1 to 2 Ohms. Tracked the trace on the board and using the manual RM451U by BirfMark (FZJ80 models with FZ-FE engine) it's the pin that receives the signal from the oxygen sensor, connector E6-pin 1 E03 transistor. - I know the manual is not specific for this truck model but the ECU seems to be the same (not same P/N), but the pin layout is the same, 4 connectors and same engine.
My questions are, does anybody know the value of the resistors so I can attempt to replace them, resolder the transistor and check the O2 sensor's harness for anything suspicious, and if anyone has encountered something similar in their ECU's perhaps the problem might come from the circuit board inside the ECU that left the transistor's gate ON and melted the soldering?
Thank you for taking the time reading this.
The transistor's circuit overheated and fell off from the board, tested it and still works correctly, measured the resistors and the show very low values, not sure if they are OK or damaged, values were in the order of 1 to 2 Ohms. Tracked the trace on the board and using the manual RM451U by BirfMark (FZJ80 models with FZ-FE engine) it's the pin that receives the signal from the oxygen sensor, connector E6-pin 1 E03 transistor. - I know the manual is not specific for this truck model but the ECU seems to be the same (not same P/N), but the pin layout is the same, 4 connectors and same engine.
My questions are, does anybody know the value of the resistors so I can attempt to replace them, resolder the transistor and check the O2 sensor's harness for anything suspicious, and if anyone has encountered something similar in their ECU's perhaps the problem might come from the circuit board inside the ECU that left the transistor's gate ON and melted the soldering?
Thank you for taking the time reading this.
