Does anyone know what codes 45 & 02 are? Or where I can find a list of codes for the PRE OBD II? 95 D1 (see signature)

Events prior to codes & CEL coming on:
Went to pick up a wrecked 94 D1 to use for parts, ~75 mile trek home with said broken D1 on ~17ft trailer. Probably close to a 6000lb gross weight. Rover in 4th gear (5spd) all the way (wouldn't really pull 5th). About 50 miles into trip CEL comes on and idle goes slightly rough, but otherwise runs fine. Actually better at highway speeds, pulls from 70-80mph much cleaner in 5th no trailer. (maybe due to ECU default setting dumping more fuel into motor?) I suspect the MAF?

Inputs? Thx in advance.

 

Ok I searched better and found the 45 code. (right bank O2 sensor). Still need info on the "02" code. Thx.

 

Credit where credit is due... taken from http://www.robisonservice.com/servicedep/rover_dept.asp

Check engine light: 1994-5 Discovery
** Note: These vehicles have both a “Check Engine” light and a “Service Engine” light. Check engine means you have a problem. Service engine means it’s been about 52,000 miles since the timer last reminded you to perform emission service. The information below pertains to Check Engine.

These fault codes will appear on a two digit display found under the passenger seat. Note that although the display can indicate fault codes up to 99 not all numbers are valid codes. You read the codes by removing the side panel of the seat base (Range Rover) or looking at the display under the back of the seat (Discovery).

Some fault codes point to a failed sensor, some indicate an engine fault that has caused the sensor to deliver an out-of-range signal, and some code may indicate either or both. Do not be too quick to replace parts on the basis of codes alone.

Here is how you clear codes once you've read them and addressed the faults:

Switch ignition on.
Disconnect serial link mating plug, wait 5 seconds, then reconnect.
Switch ignition off and wait for main relay (located under the passenger seat in Range Rovers) to drop out. Switch ignition on. The display should now be reset. If there are other faults, the next one will be displayed. Otherwise the display will be black.
If there is more than one fault repeat these steps to clear each fault until the display is blank. If you clear a code without performing a repair it (and the EFI light) may or may not return. Some codes are set by intermittent conditions that do not occur often. Other codes signal serious faults that are detected immediately upon startup.

or just pulll the Fuel Injector fuse out of circut for 10 seconds and put it back in.


On to the list of codes…
Nothing shown on display
Either nothing is wrong or the display is broken.

Code 02 - Power interruption
This code means power to the ECU has been disconnected and the truck has not yet been started. This code should go away as soon as the vehicle is started for the first time. Appearance of this code while driving may signal a problem within the ECU.

Code 12 - Airflow meter
Usually signals a problem with the airflow meter or the connector which can fall apart or become damaged. Refer to test 19, continuity test procedure.

Code 14 - Coolant sensor
Usually indicates a bad fuel injection coolant sensor. May also indicate a bad engine thermostat or a stuck viscous fan clutch. Refer to test 14, continuity test procedure.

Code 17 - Throttle potentiometer
Usually indicates a bad throttle position sensor. Refer to test 17, continuity test procedure.

Code 18 - Throttle potentiometer input high/airflow meter low
Usually indicates a problem with one of the two mentioned parts. Refer to tests 17, 18, and 19 of the continuity test procedure.

Code 19 - Throttle potentiometer input low/airflow meter high
Usually indicates a problem with one of the two mentioned parts. Refer to tests 17, 18, and 19 of the continuity test procedure.

Code 21 - Fuel tune select
Identifies that the tune select resistor is open circuit- refer to tune select resistor test. The tune resistor is embedded in the wire harness. This code may indicate damage to the wire harness.

Code 23 - Fuel supply
Check fuel system pressure, test 20 of 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 28 - Air leak
One way to check for small leaks is by spraying choke cleaner at the joint you want to check while the motor is idling. A change in tone indicates the choke cleaner is being sucked into the engine. 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 valce 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 29 - ECU memory check
If this code appears all other faults are unreliable and must be ignored. Use the procedure below to clear the code and see if it re-appears. If it does, your ECU is almost certainly bad.
Procedure:
leave battery connected
switch ignition off
wait for approximately 5 seconds
disconnect ECU plug.
reconnect ECU plug
switch ignition on and check display unit.
If fault code 29 is detected again, swap out the ECU for another one and retest.

Code 34 - Injector bank A
The 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 44 - Lambda sensor A - left bank

Code 45 - Lambda sensor B - right bank
If one of these fault codes (#44 or #45) is displayed check the wiring to that particular lambda sensor. In addition this fault will be displayed if the vehicle has a condition which causes it to run very lean or very rich on one side (example - a vacuum leak or a bad injector). This code often appears in conjunction with the misfire codes in cases of bad ignition misfire (cross-firing plug wires)
If both codes are displayed, the voltage supply to the heater coils of the sensors must be checked. Check for 12V appearing on the O2 signal lead, and check the heater circuit for shorts.

Code 48 - Stepper motor
Check base idle speed as follows:
First remove and clean the idle motor and the port it screws into. Clean the throttle body as well.
On the top of the throttle body you will see a hole (possibly covered by an anti tamper plug) for the base idle adjuster.
Remove the air bypass hose from the throttle body, which will cause the engine to speed up to 2500rpm or so. Unplug the connector to the idle motor after 5 seconds then reconnect the hose.
Squeeze the hose shut with needle nose vise grips and adjust the base idle using an allen wrench to give an idle speed of 6-700rpm. Get the lowest speed you can that gives smooth running and does not stall when blipping the throttle. Screw in for slower idle, out for faster idle.
Reconnect the idle stepper and remove the vise grip and you should be done.
In addition, refer to tests 15 and 16 of continuity test procedure. Check road speed sensor- refer to test 25 of continuity test procedure.

Code 40 - Misfire bank A - left bank

Code 50 - Misfire bank B - right bank
If one fault code 40 or 50 is displayed check components applicable to the particular bank that the misfire has occurred on:
Spark plugs
Ignition leads
Distributor cap
Injectors - if code 34 bank A or 36 bank B displayed
If both codes are displayed, check the following components common to both banks:
Distributor cap
Distributor rotor
Coil and its associated connections
Distributor pick-up (air gap)
Amplifier
Injectors (if code 34 or 36 is displayed)

Code 58 - Group faults 23/28
This indicates that a fault has been registered that is caused by the fuel supply 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.

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 88 - Purge valve leak
Refer to test 9 and 10 of the continuity test procedure.

 

Awesome! Thanks SurfRat.

Guess I'm overdue for a pair of O2 sensors anyway.

 

Where is Serial Link Mating Plug on 2003 Disco?? Does anyone have pictures??

 

The OBD2 plug is directly under the dash on the drivers side. No need to remove panel...can't miss it.