(ELECTRICAL) SE Error Code Write-Up
03-21-04, 05:58 PM
#1
(ELECTRICAL) SE Error Code Write-Up
Write up on checking GSL-SE error codes
As most of us know, the GSL-SE has a fairly simplistic fuel injection system and can be upset by several different problems. However, when everything is working correctly, the GSL-SE can be a joy to own. This write up is so the readers can take advantage of the ECU’s ability to report error codes in the GSL-SE model. I have not seen any other documentation of checking the error codes in the GSL-SE except for what is given in the Factory Service Manual (FSM), so I am hoping that this will help fellow SE owners. I will say that the error code checking is pretty simplistic in the GSL-SE, so one could have problems and there may still be no error code. The GSL-SE does report codes such as lack of signal from the trailing coil, bad Air Flow Meter (AFM), bad water thermo sensor, etc.
One will want to first refer to the FSM for 1984/1985 models of the RX-7. The FSM is separated into different systems and can be downloaded at:
http://www.wankel.net/~krwright/cars/rx7/85_manual.html
The information that we are seeking is at the end of section 4b (Fuel and Emissions 13B). The FSM states that the error codes of the ECU can be found using System checker 83 (49 G040 920) which I am sure is out of the price range of most RX-7 owners if it is still even made. The same checking procedure can be carried out using a simple LED (Light Emitting Diode) and a couple male spade terminals. The total cost of this tester is just over $2.00. For the LED, I like to use the 12V LEDs at Radio Shack. The already have the current limiting resistor in them, so that eliminates the need for solder. These LEDs are available in Red, Amber, and Green. The Radio Shack part numbers are as follows:
Amber: 276-272 $2.19
Red: 276-084 $1.99
Green: 276-271 $2.19
I recommend picking up two of them so that your tester can be used to check the TPS as well as to check for error codes. My setup uses one amber and one red LED. The tester is pretty simple to build. All that you need besides the LED is a couple male spade connectors (crimp on type work okay, but you may want to solder the connections since the wire on the LEDs is pretty fine and can be difficult to crimp a connector on). If you wish to just build the ECU checker, you will need two male spade connectors along with one LED. If you wish to also be able to check the TPS settings, you will need two LEDs along with three male spade connectors.
For the dual LED checker, connect the red wires from the two LEDs and put on a connector. The black wires each get there own connector.
For the single LED checker, connect one male spade connector to each wire (one to the red and one to the black).
Now that the connector is constructed, we can move on to looking for error codes. First, we will need to gain access to the ECU. The ECU is located under the passenger’s side floor. You will need to remove the scuff plate along the lower opening of the passenger’s side door as well as possibly the side panel that covers the passenger’s side front speaker in order to pull up the carpet. There will be a metal plate under the carpet the covers the ECU. This plate can be removed with a few 10mm nuts and bolts. Once this plate is removed, the ECU and related wiring can be seen. We will need to use the check connector in order to check for the error codes. This connector is located to the right of the ECU with nothing plugged into it. It has six terminals (3 on top and 3 on the bottom of the connector). The connector looks like:
The connector has three wires coming into it (one red, one green, one red with a white stripe). Plug the red wire from the LED into the terminal with the red wire with white stripe coming into it. Connect the black LED wire into the terminal with the red wire coming into it.
We are now reading to see if any error codes exist on the ECU. Turn the ignition to the on position (do not start), you should see the LED light up for approximately 2 seconds and then go out. If there are no error codes, then the LED will stay off after this 2 second period. However, if codes do exist, the LED will start flashing. The codes are as follows:
For example, if the water thermo sensor was bad, the LED would produce three short blinks, pause for two seconds and repeat. If there is no signal from the trailing coil after cranking for 1.5 seconds, the LED will produce a short blink, pause, and then repeat. BTW, the throttle sensor error code (code 5) will also show up if the TPS is out of adjustment.
If there is more than one code, the ECU will only display the lowest number code. So if the AFM was disconnected and the TPS was bad, the ECU would only display the code for the AFM until that problem was fixed. The GSL-SE ECU does not keep the codes in memory like the later model RX-7s, so once the problem causing the error is sorted out, one does not need to go through any steps to purge the code from memory as with later model cars.
The GSL-SE ECU is pretty simplistic with the error code checking ability with only 6 possible codes compared to the 70 or more possible codes found on newer cars. However, for its time this ability was pretty advanced.
I hope that this will benefit SE owners. I will try to include some pictures to make this more clear if I can borrow a friend's digital camera.
Kent
As most of us know, the GSL-SE has a fairly simplistic fuel injection system and can be upset by several different problems. However, when everything is working correctly, the GSL-SE can be a joy to own. This write up is so the readers can take advantage of the ECU’s ability to report error codes in the GSL-SE model. I have not seen any other documentation of checking the error codes in the GSL-SE except for what is given in the Factory Service Manual (FSM), so I am hoping that this will help fellow SE owners. I will say that the error code checking is pretty simplistic in the GSL-SE, so one could have problems and there may still be no error code. The GSL-SE does report codes such as lack of signal from the trailing coil, bad Air Flow Meter (AFM), bad water thermo sensor, etc.
One will want to first refer to the FSM for 1984/1985 models of the RX-7. The FSM is separated into different systems and can be downloaded at:
http://www.wankel.net/~krwright/cars/rx7/85_manual.html
The information that we are seeking is at the end of section 4b (Fuel and Emissions 13B). The FSM states that the error codes of the ECU can be found using System checker 83 (49 G040 920) which I am sure is out of the price range of most RX-7 owners if it is still even made. The same checking procedure can be carried out using a simple LED (Light Emitting Diode) and a couple male spade terminals. The total cost of this tester is just over $2.00. For the LED, I like to use the 12V LEDs at Radio Shack. The already have the current limiting resistor in them, so that eliminates the need for solder. These LEDs are available in Red, Amber, and Green. The Radio Shack part numbers are as follows:
Amber: 276-272 $2.19
Red: 276-084 $1.99
Green: 276-271 $2.19
I recommend picking up two of them so that your tester can be used to check the TPS as well as to check for error codes. My setup uses one amber and one red LED. The tester is pretty simple to build. All that you need besides the LED is a couple male spade connectors (crimp on type work okay, but you may want to solder the connections since the wire on the LEDs is pretty fine and can be difficult to crimp a connector on). If you wish to just build the ECU checker, you will need two male spade connectors along with one LED. If you wish to also be able to check the TPS settings, you will need two LEDs along with three male spade connectors.
For the dual LED checker, connect the red wires from the two LEDs and put on a connector. The black wires each get there own connector.
For the single LED checker, connect one male spade connector to each wire (one to the red and one to the black).
Now that the connector is constructed, we can move on to looking for error codes. First, we will need to gain access to the ECU. The ECU is located under the passenger’s side floor. You will need to remove the scuff plate along the lower opening of the passenger’s side door as well as possibly the side panel that covers the passenger’s side front speaker in order to pull up the carpet. There will be a metal plate under the carpet the covers the ECU. This plate can be removed with a few 10mm nuts and bolts. Once this plate is removed, the ECU and related wiring can be seen. We will need to use the check connector in order to check for the error codes. This connector is located to the right of the ECU with nothing plugged into it. It has six terminals (3 on top and 3 on the bottom of the connector). The connector looks like:
The connector has three wires coming into it (one red, one green, one red with a white stripe). Plug the red wire from the LED into the terminal with the red wire with white stripe coming into it. Connect the black LED wire into the terminal with the red wire coming into it.
We are now reading to see if any error codes exist on the ECU. Turn the ignition to the on position (do not start), you should see the LED light up for approximately 2 seconds and then go out. If there are no error codes, then the LED will stay off after this 2 second period. However, if codes do exist, the LED will start flashing. The codes are as follows:
For example, if the water thermo sensor was bad, the LED would produce three short blinks, pause for two seconds and repeat. If there is no signal from the trailing coil after cranking for 1.5 seconds, the LED will produce a short blink, pause, and then repeat. BTW, the throttle sensor error code (code 5) will also show up if the TPS is out of adjustment.
If there is more than one code, the ECU will only display the lowest number code. So if the AFM was disconnected and the TPS was bad, the ECU would only display the code for the AFM until that problem was fixed. The GSL-SE ECU does not keep the codes in memory like the later model RX-7s, so once the problem causing the error is sorted out, one does not need to go through any steps to purge the code from memory as with later model cars.
The GSL-SE ECU is pretty simplistic with the error code checking ability with only 6 possible codes compared to the 70 or more possible codes found on newer cars. However, for its time this ability was pretty advanced.
I hope that this will benefit SE owners. I will try to include some pictures to make this more clear if I can borrow a friend's digital camera.
Kent
Last edited by vipernicus42; 09-20-06 at 08:32 AM.
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03-22-04, 11:04 AM
#8
84SE-EGI helpy-helperton
Very nice job - I have been seriously considering the $544 purchase at Mazdatrix for the Mazda Factory "Code Checker" that is referenced in the FSM, but have kept putting it off because of other, more pressing (and worthwhile) expenses. If you recall, the Factory "Code Checker" provides an auditory note (which can be built, if you're inventive), and also checks other codes on the car for adjustment and correct readings.
Now that you've written this up - you've saved me $544! Thanks!
Now that you've written this up - you've saved me $544! Thanks!
Last edited by LongDuck; 03-22-04 at 11:07 AM.
03-22-04, 12:20 PM
#9
Thanks guys for all your kind words.
Manntis: I would be honored to have you put this on your site. Eventually, I will have to have the pics hosted on another site. I have this space since I am a graduate student. I will lose this space in about 1.5 years. Manntis, maybe you could also put the pics on your server.
LongDuck: I figured that code checker would be expensive, but $544?
It looks like the code checker is two LEDs and a buzzer. You really don't need the buzzer and the other LED is to check O2 sensor readings. I think that I could maybe come up with something that included the buzzer and the O2 sensor readings if people were interested.
I basically came up with this because I wanted to see if my SE had any error codes. I knew the checker would be expensive and probably not needed. So, I looked at the wiring diagrams and the codes in the FSM. I built a tester (I also use it for TPS adjustment) and found that I had an AFM error code. I replaced it with a used one and the error went away. I also checked the AFM with my DMM and found that the resistances between two of the terminals were not within spec. So, the ECU did do a good job detecting the error.
Kent
Manntis: I would be honored to have you put this on your site. Eventually, I will have to have the pics hosted on another site. I have this space since I am a graduate student. I will lose this space in about 1.5 years. Manntis, maybe you could also put the pics on your server.
LongDuck: I figured that code checker would be expensive, but $544?
It looks like the code checker is two LEDs and a buzzer. You really don't need the buzzer and the other LED is to check O2 sensor readings. I think that I could maybe come up with something that included the buzzer and the O2 sensor readings if people were interested.I basically came up with this because I wanted to see if my SE had any error codes. I knew the checker would be expensive and probably not needed. So, I looked at the wiring diagrams and the codes in the FSM. I built a tester (I also use it for TPS adjustment) and found that I had an AFM error code. I replaced it with a used one and the error went away. I also checked the AFM with my DMM and found that the resistances between two of the terminals were not within spec. So, the ECU did do a good job detecting the error.
Kent
03-22-04, 05:19 PM
#10
FD > FB > FC
Geeze had I known that you all didnt know this, I would have done a writeup along time ago for this. I had to do it for my S5 fuel injection more times than I want to remember.
