How to check diagnostic codes

cre · 12-27-2011, 08:30 PM

I haven't looked to see if this has all that's missing from the Cygnus list but it's been point out that some codes are not listed there. Here's a list I've compiled from a couple different TSRMs using TCCD ECUs (Valid for 1986 - 1995... I think they were actually using up to 98 or so in some vehicles but that may not be the case with the USDM).

Code 11 Momentary interruption in power supply to ECU (electronic control unit or computer) up to 1991
Code 12 Engine revolution signal missing
Code 13 Rpm signal to ecu missing above 1000 rpm
Code 14 Igniter signal to ecu missing
Code 16 A/T control signal missing from ecu
Code 21 Main oxygen sensor signal fault
Code 22 Water temperature sensor circuit fault
Code 23 and 24 Intake air temperature signal fault
Code 25 Air/fuel ratio LEAN
Code 26 Air/fuel ratio RICH
Code 27 Sub-oxygen sensor signal or heater circuit fault
Code 28 No.2 oxygen sensor/heater signal fault
Code 31 and 32 Air flow meter circuit or Vacuum sensor signal fault
Code 34 and 36 Turbo-charging pressure signal fault
Code 35 Altitude compensation sensor signal fault
Code 41 Throttle position circuit fault
Code 42 Vehicle speed sensor circuit
Code 43 No starter signal to the ecu
Code 47 sub-tps circuit fault or idl2 and vta2 voltage too high (>1.5v) (JDM ONLY???)
Code 51 AC signal on; IDL switch open (part of the TPS). This code will only appear if the IDL switch is open (ie: you're stepping on the throttle in diag mode or the TPS is not properly calibrated) or the A/C system is on or says it is. When the cause of the code is corrected it will automatically remove itself, no need to reset the ECU.
Code 52, 53 and 55 Knock sensor fault
Code 71 EGR system malfunction
Code 72 Fuel cut solenoid signal fault
Code 78 Fuel pump control signal fault
Code 81, 83, 84 and 85 TCM communication fault

12-27-2011, 08:30 PM	#11
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	I haven't looked to see if this has all that's missing from the Cygnus list but it's been point out that some codes are not listed there. Here's a list I've compiled from a couple different TSRMs using TCCD ECUs (Valid for 1986 - 1995... I think they were actually using up to 98 or so in some vehicles but that may not be the case with the USDM). Code 11 Momentary interruption in power supply to ECU (electronic control unit or computer) up to 1991 Code 12 Engine revolution signal missing Code 13 Rpm signal to ecu missing above 1000 rpm Code 14 Igniter signal to ecu missing Code 16 A/T control signal missing from ecu Code 21 Main oxygen sensor signal fault Code 22 Water temperature sensor circuit fault Code 23 and 24 Intake air temperature signal fault Code 25 Air/fuel ratio LEAN Code 26 Air/fuel ratio RICH Code 27 Sub-oxygen sensor signal or heater circuit fault Code 28 No.2 oxygen sensor/heater signal fault Code 31 and 32 Air flow meter circuit or Vacuum sensor signal fault Code 34 and 36 Turbo-charging pressure signal fault Code 35 Altitude compensation sensor signal fault Code 41 Throttle position circuit fault Code 42 Vehicle speed sensor circuit Code 43 No starter signal to the ecu Code 47 sub-tps circuit fault or idl2 and vta2 voltage too high (>1.5v) (JDM ONLY???) Code 51 AC signal on; IDL switch open (part of the TPS). This code will only appear if the IDL switch is open (ie: you're stepping on the throttle in diag mode or the TPS is not properly calibrated) or the A/C system is on or says it is. When the cause of the code is corrected it will automatically remove itself, no need to reset the ECU. Code 52, 53 and 55 Knock sensor fault Code 71 EGR system malfunction Code 72 Fuel cut solenoid signal fault Code 78 Fuel pump control signal fault Code 81, 83, 84 and 85 TCM communication fault __________________ If something breaks or you need to contact a member of the administration please post HERE. Unless it's a private or administration matter please post it on the forum. It benefits no one else if car related questions aren't posted for future users and takes away from the time I'm able to spend helping on the rest of the forum. If you're so inclined I'm always more than happy to accept tips via PayPal. Tip Jar ---> Last edited by cre; 04-19-2012 at 07:28 AM. Reason: added more info.