From: crash@merl.com Date: Fri, 23 Feb 1996 09:48:06 -0500 Subject: Discovery diagnostic readout codes!
I have good news: Discoveries have a digital diagnostic readout box built in; it's under the passenger seat, facing backwards, and looks like a black plastic box about 1" x 2.5" x 3". It's actually deep red semitransparent plastic and it contains a red LED readout with no segments illuminated if nothing's broke. It's clipped under the seat, and can be unclipped and positioned where the driver can see it.
It doesn't give anything close to what Testbox gives, but it's in the car already. (note- this may or may not apply to the 96's with OBD II systems built in)
The folks at Land Rover Metro West even gave me a photocopy of the codes, which I reproduce below:
--- human typein follows ---
Description of fault codes:
The fault codes are listed in order of priority. Where more than one fault exists, clearing the first fault code will permit the next code to be displayed.
Note: fault code 02 will show if the ECU has just been reconnected. Switch on ignition to clear the display.
Clearing fault code display"
It is necessary to clear the code displayed when the fault has been rectified, and to access any further fault codes that may exist. Clear the fault code displayed by the following procedure:
1) Switch ON ignition.
2) disconnect serial link mating plug, wait 5 seconds, reconnect.
3) switch OFF ignition, wait for main relay to drop out.
4) Switch ON ignition. The display should now be reset. If no other faults exist, and the original fault has been rectified, the display will be blank.
5) if multiple faults exist repeat steps 1 to 4, as each fault is cleared the code will change until all faults are cleared. The display will now be blank.
CODE 29 - ECU memory check. If this fault is detected, all other faults are unreliable and must therefore be ignored.
Proceed as follows:
1) leave battery connected 2) switch ignition off 3) wait for approximately 5 seconds 4) disconnect ECU plug. 5) reconnect ECU plug 6) switch ignition on and check display unit.
NOTE: if fault code 29 is detected again, substitute ECU and restart test sequence.
CODE 44 - Lambda sensor A - left bank CODE 45 - Lambda sensor B - right bank
If one of these fault codes is displayed check the wiring to that particular lambda sensor.
If both codes are displayed, the voltage supply to the heater coils of the sensors must be checked. Refer to test 26, continuity test procedure.
CODE 25 - Ignition misfire
This code indicates that an ignition system misfire has been detected. Codes 40 or 50 indicate on which bank the misfire has occurred.
CODE 40 - Misfire bank A - left bank
CODE 50 - Misfire bank B - right bank
If both fault codes are displayed, check the following components common to both banks:
Distributor cap rotor arm coil electrical connectioins pick-up (air gap) amplifier injectors (if code 34 or 36 is displayed)
If either fault code 40 or 50 is displayed check components applicable to the particular bank that the misfire has occurred on.
Spark plugs HT leads distributor cap Injectors - if code 34 bank A or 36 bank B displayed
CODE 12 - Airflow meter. Refer to test 19, continuity test procedure.
CODE 21 - fuel tune select - identifies that the tune select resistor is open circuit- refer to tune select resistor test.
CODE 34 - Injector bank A - dhe display will indicate if the injector(s) are causing the engine to run rich or lean.
If the bank is running rich, check for - faulty injector wiring and connectors, stuck open injectors.
If the bank is running lean, check for - faulty injector wiring and connectors, blocked injectors.
CODE 36 - Injector bank B - as code 34, except relevant to bank A injectors.
CODE 14 - Coolant thermistor - refer to test 14, continuity test procedure.
CODE 15 - Fuel thermistor, refer test 13 [27/2/96]
CODE 17 - Throttle potentio meter - refer to test 17, continuity test procedure.
CODE 18 - Throttle potentiometer input high/airflow meter low - refer to tests 17, 18, and 19 of the continuity test procedure.
CODE 19 - Throttle potentiometer input low/airflow meter high - refer to tests 17, 18, and 19 of the continuity test procedure.
CODE 88 - Purge valve leak - refer to test 9 and 10 of the continuity test procedure.
CODE 28 - Air leak - check for air leaks in the following areas:
hose, air flow meter to plenum
breather system hoses to plenum
brake servo hose
vacuum reservoir hose (fresh air solenoid)
distributor vacuum advance
hose, purge valve to plenum injector seals
joint - bypass air valve to plenum,
plenum chamber to ram housing,
ram housing to inlet manifold,
inlet manifold to cylinder head,
bypass air valve hose
CODE 23 - Fuel supply - check fuel system pressure, test 20 of continuity test procedure.
CODE 48 - Stepper motor - check base idle speed- see setting procedure. Refer to tests 15 and 16 of continuity test procedure. Check road speed sensor- refer to test 25 of continuty test procedure.
CODE 68 - Road speed sensor - refer to test 25 of continuity test procedure.
CODE 69 - Gearswitch - refer to test 24 of continuity test procedure.
CODE 59 - group faults 23/28. This indicates that a fault has been registered that is caused by the fuel spply or an air leak but the exact fault cannot be identified. Check all items outlined under codes 23 and 28.
Code 59 - Fuel thermistor - Refer to test 13 of the continuity test procedure.
-Bill ©
From: crash@merl.com Date: Mon, 26 Feb 1996 09:35:28 -0500 Subject: Disco Diagnostic Code updates, ABS info.[...]
The data link pair is kinda funky- imagine a cable that ends in a connector with two wires spliced back out of the connector. Now, plug in a mating connector to the one on the end of the cable, and run the two spliced-back wires back into the connector end you just added.
-Bill ©