Engine code help needed!

[badmuthatrucka]

So, I already have one thread up because of other problems.

I need to get the 80 to pass emissions here in Las Vegas, which means it has to pass being hooked up to an engine code reader. All they do is check to see if your vehicle is supposed to have its CEL on, and that determines whether or not you pass.

I pulled the codes yesterday, and came away with five. I have codes 41,42, 83, 84, and 85. I know that the 83-85 codes mean that I need a new ECU/ECM, but I'm stumped on what to do for the 41 and 42. I have no garage and limited tools, but I do have a multi-meter and some test leads.

Any help would be greatly appreciated!

 

[Kernal]

Here's two slightly different lists:

Toyota OBD1 Codes

1 Normal Condition.
2 Air Flow Meter signal.
3 Ignition signal.
4 Engine Coolant Temperature Sensor signal.
5 Oxygen Sensor.
6 RPM signal (Crank Angle Pulse).
7 Throttle Position Sensor signal.
8 Intake Air Temperature Sensor signal.
9 Vehicle Speed Sensor signal.
10 Starter signal.
11 Switch signal.
11 ECU/ECM.
12 Knock Control Sensor signal.
12 RPM signal.
13 Knock Control CPU (ECM).
13 RPM signal.
14 Turbocharger Pressure.
14 Ignition signal.
21 Oxygen Sensor.
22 Engine Coolant Temperature Sensor signal.
23 Intake Air Temperature Sensor signal.
24 Intake Air Temperature Sensor signal.
25 Air-Fuel Ratio Lean.
26 Air-Fuel Ratio Rich.
27 Sub Oxygen Sensor signal.
28 No. 2 Oxygen Sensor signal.
31 Air Flow Meter signal (Vacuum Sensor signal).
32 Air Flow Meter signal.
34 Turbocharger Pressure signal.
35 Turbocharger Pressure Sensor signal.
35 HAC Sensor signal.
41 Throttle Position Sensor signal.
42 Vehicle Speed Sensor signal.
43 Starter signal.
51 Switch signal.
52 Knock Sensor signal.
53 Knock Sensor signal.
54 Inter-cooler ECM signal.
71 EGR System.
72 Fuel Cut Solenoid signal.
78 Fuel Pump Control signal.
81 TCM Communication.
83
TCM Communication.
84 TCM Communication.
85 TCM Communication.


Toyota OBD I codes:

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 51 AC signal on; DL contact off (in trany shifter with diagnostic connector jumped)
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

This list is the about the same just uses slightly different wording:

 

[SiRaDuDe]

Pull the EFI fuse in the engine bay, clear all codes.

See how long it takes for the coeds to come back on... maybe you can clear the codes just before the test and you might have enough time to pass the test before they pop back up...

 

[jonheld]

it has to pass being hooked up to an engine code reader.

No it doesn't. Your truck is OBD1. No code reader used as there is no place to plug one in.

 

[firetruck41]

No it doesn't. Your truck is OBD1. No code reader used as there is no place to plug one in.

Thats what I was thinking. Usually around here, if it doesn't have obd2, it just has to pass a sniffer test.

 

[badmuthatrucka]

Perhaps that is my problem. I believe all the people I have spoken with have OBDII vehicles. I'll have to check on that. Thanks for the heads up!

 

[kidglove13]

No code checking on a OBD I truck
Just make sure that you dont have a check engine light on for the inspection
But who knows even without the CEL on you might not pass because of the other issues steming from the CEL
you might not pass the sniffer test.
You are throwing quite a few codes there, you need to check some things out

 

[badmuthatrucka]

Passed with flying colors. The CEL came back on right after the tech got back out of the truck.

The codes don't seem to actually make any difference to the exhaust. Maybe once I start getting paid for my new job I can start saving up for a new ECM.

 

[LCHardriver_02]

Ever since I bought our 80, I have been chasing codes. It started with the P0402 (mine is a 95 with ODBII) while driving away from the dealership, it went to about 5 other codes, while I cleaned the engine, replaced fluids, removed the battery for a day to install an audio amp, drove down a dirt road throwing up a ton of dust, etc.

Fact was, I passed emissions anyway. It sounds like you may be running down the same path. I am trying to maintain patience while slowly troubleshooting my various small issues that have been causing the CEL to continuously pop up. So far (knock on simulated wood veneer), I have not had any that have caused "real" trouble with the truck.

Good luck in your investigations.