Consider substituting a known working ECU that is compatible with your van if you are unable to locate the problem it is also possible to test the ECU itself with the aid of the Factory Service Manual and/or Electrical Wiring Diagram manual specific to your van’s model year.Īll ECUs have the part number on the case use the part numbers below to assess possible compatibility. Reading The On/Off Flashes Of The Check Engine Light In a nutshell, to get the trouble codes stored in your Camry's fuel injection computers's memory, we need to jumper together 2 specific terminals of the diagnostic link connector (DLC). About SRS The self-diagnosis codes are read out in the same way as the others, in terms of the number of flashes of the 'SRS' indicator when the terminals 'TC' - 'CG' (13-4) of the DLC3 connector under the dashboard are closed and the ignition is switched on.
For all problems and codes, it is possible (although highly uncommon) for an internal ECU malfunction to be the source of the trouble code. Toyota OBD I Diagnostic Trouble Code Definitions.About half of the ECU codes stored on the first & second generation EFI Toyotas dont show a constant blinking check engine light therefore you must pull the ECU codes to see if a fault is.
The use of Allison DOC For PCService Tool is described in the instruction manual furnished with each tool. Code 31Air flow meter, to see full codes see below also measure the voltages and reistances on ECU and compare with service manual to isolate problem. DTC READING AND DTC CLEARING DTCs can be read and cleared by using Allison DOC For PCService Tool. To verify that a trouble area has been successfully repaired, you will need to clear the codes (see above) and run the engine (and possibly road test the van, depending on the exact malfunction) before checking for codes again. DIAGNOSTIC TROUBLE CODES (DTC) 10 PRODUCT FAMILIES TROUBLESHOOTING MANUALALLISON 4th GENERATIONCONTROLS 53.Lower temperatures require longer disconnect times. Toyota states “30 seconds or longer depending on the ambient temperature,” for the 3Y vans, but only “10 seconds or longer depending on the ambient temperature” for the 4Y vans. To clear codes from the ECU’s memory after a repair, remove the EFI fuse ( click here to locate) with the ignition switch off OR disconnect the battery.For an example of how the "check engine" light behaves when a van is throwing two codes, click here.For all vans, a steady blinking light (single blink) is your verification that the diagnostic system is functioning and has no stored codes.On '83 through '85 Cressida and Supra models, the check engine light does not flash diagnostic codes. Low voltage on T causes the ECU to enter diagnostic mode, producing diagnostic codes on the check engine light.
To learn how to check your van for stored trouble codes, click here When the T terminal is grounded with the ignition switch in the 'on' position, the ECU sees the voltage at terminal T go low.