Engine Warning Light & Fault Codes

[trilogy]

My other half's 2nd gen 3.0 TD Surf has jus developed a problem with the engine warning light coming on indermittantly, along with a complete loss of power (top speed now 20-30 mph).

I've searched the forums on why this may be happening, and can't seem to find anything directly related on the forum.

Can someone point me in the direction of how (and where) to read the engine codes? I'm at a complete loss..

[jaky cakes]

found this....

All Toyota vehicles with electronic fuel injection utilize the Toyota EFI or TCCS engine management system. This system incorporates many features to enhance performance, emissions, and drivability. One feature is the Self Diagnostic System. The self diagnostic system monitors engine operations and when a particular sensor or input varies out of specified operating parmeters, the "Check Engine" will be illuminated.

The check engine lamp alerts the driver or technician that a problem exists in the EFI/TCCS ECU or Engine Control Unit or "computer." When the check engine light is illuminated, it is indicating that a problem in the engine management system has been detected. At this time, a "code" may be stored in the ECU which pinpoints a possible component in the EFI/TCCS system. By checking the trouble codes, a possible problem could be narrowed down to a number of causes. While not an exact diagnostic tool, the check engine light and self-diagnostic system can get the individual working on his/her truck close to a possible fault, and, hopefully, to a successful repair.

Listed below are one and two digit trouble codes for the EFI/TCCS systems and possible causes. As mentioned above, this is not an exact science. Many other component failures can cause similar symptoms that can "mask" the actual cause. EFI/TCCS computer interrogation is one of the last steps to engine diagnostics. A thourough inspection of the simple items should be done prior to any computer-related repairs. Sometimes it's the simple things that will get ya'. In addition, use caution when working on the electrical system of your vehicle. Not only is the electrical system delicate to water, static electricity, and outright physical abuse, the ignition system puts out high voltage as well and you can be serioulsy injured if you do not exercise basic safety.

READING THE TROUBLE CODES

Reading the diagnostic trouble codes is very easy. You will need a paper clip to short the check connectors of the diagnostic connector. The diagnostic connector comes in two types. The early system is located on the inner-left fender well and is a round, green connector, usually located near the air cleaner. Simply jump the two terminals in this connector with the ignition switch in the "ON" position and the engine off. Later models, '87 and newer use a multiple terminal "DIAGNOSTIC" connector which is a small, rectangular-shaped grey "box", usually located near the right fender in the enigne compartment. To get codes out of this type of connector, jump the "TE1" and "E1" teminals. Finding these terminals is easy as the inside cover of the diagnostic connector contains a schematic of the connector pinouts. If the underhood emission decal (VECI) is still intact on your vehicle, the proper pins for this are outlined there as well.

The trouble codes will appear as flashes of the check engine lamp. Be sure the ignition key is on, the engine off, and your foot off of the accelerator when reading the codes. Two different codes may appear: One-digit and two digit. One digit codes have an approximate 4.5 second delay between flashes with the check engine light illuminating for about a half of a second. Mulitiple codes have a 2.5 second delay between them. For example a code two flashes the check engine lamp two times in a little over one second: I I. If two codes are stored, such as a code two and a code four, the lamp may flash as such: ....I I....I I I I. Crude examples but you get the idea. Two digit codes are similar but will flash the lamp with the first number first and the second number last. An example of a code twleve is I ....II and a code twenty four is I I..IIII.



Later-model EFI/TCCS Diagnositc Connector

(Photo courtesey of Chris Geiger)



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TROUBLE CODES AND POSSIBLE CAUSES

ONE-DIGIT TWO-DIGIT POSSIBLE CAUSE OF CODE/SYMPTOM
1
NONE
SYSTEM NORMAL

--
11
LOSS OF POWER SUPPLY TO ECU
--IGNITION SWITCH/CIRCUIT

--MAIN RELAY/CIRCUIT

--ECU

6
12
RPM SIGNAL-NO SIGNAL TO ECU FROM DISTRIBUTOR ("Ne" OR "G") AFTER ENGINE HAS BEEN CRANKED
--DISTRIBUTOR/CIRCUIT

--STARTERSIGNAL CIRCUIT

--IGNITER/IGNITER CIRCUIT

--ECU

--
13
SAME AS ABOVE BUT AFTER ENGINE HAS RUN AT 1,000-1,500 RPM
--DISTRIBUTOR/DISTRIBUTOR CIRCUIT

--ECU

3
14
IGNITION SIGNAL--NO "IGF" SIGNAL TO ECU
--IGNITER/IGNITER CIRCUIT

--IGNITER AND IGNITION COIL/CIRCUIT

--ECU

5
21
OXYGEN SENSOR SIGNAL/OXYGEN SENSOR HEATER SIGNAL
OPEN OR SHORT IN OXYGEN SENSOR OR OXYGEN SENSOR SIGNAL

4
22
WATER TEMPERATURE SENSOR SIGNAL--OPEN OR SHORT IN WATER TEMP. SENSOR SIGNAL
--WATER TEMPERATURE SENSOR CIRCUIT

--WATER TEMPERATURE SENSOR

--ECU

8
24
INTAKE AIR TEMPERATURE SENSOR SIGNAL--OPEN OR SHORT IN INTAKE AIR TEMP. SIGNAL
--INTAKE AIR TEMPERATURE CIRCUIT

--INTAKE AIR TEMPERATURE SENSOR

--ECU

--
25
AIR/FUEL RATIO LEAN INDICATOR--LEAN SIGNAL SENT TO ECU FROM O2 SENSOR
--INJECTOR FAULT(S)

--FUEL PRESSURE

--OXYGEN SENSOR

--AIRFLOW METER OR MAP SENSOR

--IGNITION

--ECU

--
26
AIR/FUEL RATIO RICH INDICATOR
--SAME AS ABOVE

--COLD START INJECTOR

--
27
SUB-OXYGEN SENSOR CIRCUIT OR SUB-OXYGEN SENSOR HEATER CIRCUIT
--SUB OXYGEN SENSOR/HEATER/CIRCUIT

--ECU

--
28
No.2 OXYGEN SENSOR/OXYGEN SENSOR HEATER
--SAME AS CODE 21

2
31
MANIFOLD AND/OR AIRFLOW METER SENSOR SIGNAL CIRCUIT
--AIRFLOW METER/CIRCUIT

--MANIFOLD PRESSURE SENSOR/CIRCUIT

--ECU

--
32
AIRFLOW METER SIGNAL (VANE-TYPE)
--AIRFLOW METER./CIRCUIT

--ECU

14
34
TURBOCHARGER PRESSURE--ABNORMAL TURBOCHARGER PRESSURE
--TURBO CHARGER

--AIRFLOW METER/MANIFOLD/TURBOCHARGER PRESSURE SENSOR

--INTERCOOLER SYSTEM

--ECU

--
35
TURBOCHARGER PRESSURE SENSOR SIGNAL
--TURBOCHARGER PRESSURE SENSOR

--ECU

7
41
THROTTLE POSITION SENSOR SIGNAL--OPEN OR SHORT IN TPS SIGNAL
--TPS SENSOR

--TPS SIGNAL/CIRCUIT

--ECU

9
42
VEHICLE SPEED SENSOR SIGNAL CIRCUIT--NO SPD. SIGNAL FOR SEVERLA SECONDS
WHILE VEHICLE IS OPERATED UNDER HEAVY LOAD (TPS/MAP/AIR FLOW INPUTS)

--SPEED SENSOR/CIRCUIT

--ECU

10
43
STARTER SIGNAL--NO "STA" SIGNAL TO ECU UNTIL ENGINE SPEED EXCEEDS 800RPM
--IGNITION SWITCH/CIRCUIT

--ECU

11
51
SWITCH SIGNALS
IDL (tps) CONTACTS OFF, NEUTRAL START SWITCH OFF, A/C SWITCH "ON" SIGNAL TO ECU

WITH DIAGNOSTIC CHECK CONNECTOR SHORTED

--A/C SWITCH/CIRCUIT

--A/C AMPLIFIER

--TPS/CIRCUIT

--NEUTRAL START SWITCH/CIRCUIT

--ECU

12
52
KNOCK SENSOR SIGNAL--OPEN OR SHORT IN KNOCK SENSOR SIGNAL
--KNOCK SENSOR/CIRCUIT

ECU

13
53
KNOCK CONTROL SIGNAL IN ECU
--ECU

--
71
EGR VALVE MALFUNCTION--EXHAUST GAS TEMPEATURE BELOW SPEC. FOR EGR CONTROL
--EGR SYSTEM

--EGR GAS TEMPERATURE SENSOR/CIRCUIT

- -
72
AIR CONDITIONER COMPRESSOR RELAY/RELAY SIGNAL
--A/C COMPRESSOR RELAY/CIRCUIT

--ECU


While a lot of the possible faults in the EFI system point to the ECU iteself, it should be noted that ECU failure is not common. The ECU should be replaced only as a last resort or if all diagnosises points to a bad ECU. Usually, troublesome EFI problems are a result of poor grounds, shorted wiring, and bad connectons at sensors.When all else fails, carefully consult your factory repair manual. It contains more comprehensive diagnostic information and great electrical wiring diagrams.

Happy "Diagnosticating!"

[Taliesins]

Phew you forgot to mention that if the OD light starts flashing this is pointing to a fault in the Auto Gearbox.

[trilogy]

Wow! thanks guys. That's a lot of info there. The light doesn't seem to be flashing, I just had to drive it over to the next village to park it up for the night (hopeful pre-inspection tomorrow morning) and the light came on and stayed on. Wouldn't do more than 10-20 mph and any touch on the throttle resulted in clouds of white smoke out of the exhaust. I stopped a couple of times on the way over to let the traffic pass, then when pulling away found it would pick up as normal then slow down again to the same 10-20mph.

Anyone know of any knowledgeable garages in the Bedfordshire region? I'm loathed to get it trailered to any Toyota service centre as I think I may be drained of all of my assets!

Thanks for the responses though - good to know there's other likeminded owners out there.

Dean (self confessed complete newb)

[MattF]

Might be worthwhile checking the vacuum pipes as well.

[trilogy]

Hi All,

Just managed to extract a code from the connector just now.. If I'm interpreting the details correctly I'm getting a single flash, then a break of around 4 seconds then four quicker pulses. I guess this means a single code 14.. right?!

This then should mean possibly;

14
34
TURBOCHARGER PRESSURE--ABNORMAL TURBOCHARGER PRESSURE
--TURBO CHARGER

--AIRFLOW METER/MANIFOLD/TURBOCHARGER PRESSURE SENSOR

--INTERCOOLER SYSTEM

--ECU

Or am I going mad?

Additinally, thanks to tony at 4x4 toys today for helping me understand what I might be in for. I'm definately coming to you for service once I get this bugger running again!

thanks

Dean

[trilogy]

oops,

Now I've noticed that the O/D light is flashing! Oh dear does this mean a very costly transmission rebuild?!

[Taliesins]

oops,

Now I've noticed that the O/D light is flashing! Oh dear does this mean a very costly transmission rebuild?!

No, one fault could be causing the other or if the ECU hasnt been cleared could be a previous fault, to clear the ECU disconnect the baterry's for about 20 minutes

[trilogy]

Another call to Tony @ 4x4 toys today strongly suggests that the fault codes in the top part of this mail may be for the 2.4 perhaps, as apparently a code 14 means something to do with the timer control system malfunction (fueling).

Gonna take the pump off and replace the filter and check all the connections before I go any further. Toyota want almost £30 for a Diesel filter, disgraceful! Needless to say I won't be getting one from them!

Trilogy

[Taliesins]

Another call to Tony @ 4x4 toys today strongly suggests that the fault codes in the top part of this mail may be for the 2.4 perhaps, as apparently a code 14 means something to do with the timer control system malfunction (fueling).

Gonna take the pump off and replace the filter and check all the connections before I go any further. Toyota want almost £30 for a Diesel filter, disgraceful! Needless to say I won't be getting one from them!

Trilogy

this link will give you the codes
http://www.off-road.com/toyota/tech/codes/index.html

14 is no IGF signal to ECU
iigniter/igniter circuit
igniter and ignition coil /circuit

[trilogy]

But as the rest period between the end and start of the code is just over 4 seconds, I have to assume that this is a single digit code 14.. which leads me straight back to
14
TURBOCHARGER PRESSURE--ABNORMAL TURBOCHARGER PRESSURE

--TURBO CHARGER

--AIRFLOW METER/MANIFOLD/TURBOCHARGER PRESSURE SENSOR

--INTERCOOLER SYSTEM

--ECU

[MattF]

When was your airfilter last changed?

[trilogy]

The airfilter is about 3 months old (about the same time we got hold of the Surf)

I think I've cured the problem now as it appears that the fault may have been with the filter mechanism itself. I've swapped it out with one from a Ford pickup and it seems 100% now, pulls lovely, no smoke and no bad ECU code!

Also put in another smaller inline filter before the main one, and have also introduced a small marine type hand pump.

Fingers crossed all is now a-ok. From what I've learned these 3 litre units are pretty bullet proof so I was banking on it being something small (but nonetheless frustrating!) all in all it's cost me £40 so I'm not complaining!

Thanks all

Dean

[MattF]

Is it the fuel filter assembly that uses the smaller bodied Motorcraft
filter found in a lot of Ford diesels? The one with the top bolt for
dropping the filter off.

[trilogy]

That sounds very much like the one. My mate came over and fitted it on (with some slight bracket modification) this morning. Not only that, they'll be a lot more common to get your hands on and also cheaper in most cases too..