GEMS OBD2

OBD2
from the California Authorities

"OBD II is an acronym for On-Board Diagnostic II, the second generation of on-board self-diagnostic equipment requirements for light- and medium-duty California vehicles. On-board diagnostic capabilities are incorporated into the hardware and software of a vehicle's on-board computer to monitor virtually every component that can affect emission performance. Each component is checked by a diagnostic routine to verify that it is functioning properly. If a problem or malfunction is detected, the OBD II system illuminates a warning light on the vehicle instrument panel to alert the driver. This warning light will typically display the phrase "Check Engine" or "Service Engine Soon," and will often include an engine symbol. The system will also store important information about any detected malfunction so that a repair technician can accurately find and fix the problem."

WATCHPOINT: 2004 An OBD2 reader can only work, to a varying and dubious degree, with Morgans. It should not be relied on. Many of the codes the reader will produce are missing, odd or wrong. In the case of a Morgan GEMS Plus 8, an owner should equipe himself and his Morgan with a proper LR GEMS diagnostic tool. I posted recommendations on GoMoG up in 2003, along with the David Poole Gems Manual, which was made for GoMoG. If you have nothing else to go by, you can use a Rover dealer and tell them that the system is similiar to Discovery II (a 1996 system), but that is a risk because it is not identical. Additionally, engine management program systems age rapidly and Morgan uses older tyechnology than current. GEMS, for Land Rover dealers, was dated when you received your Morgan. It was closest to a 1996 Discovery II. That Morgan GEMS, installed long after GEMS was shelved by LR, woefully obsolete for them. Please obtain a PROPER diagnostic unit as soon as you can after receiving the car.

I am adding add the list of Discovery 2 codes here. It is moe extensive than the Poole Manual's List.

Land Rover: 96 – Up OBD2 Diagnostic Trouble Codes

With a Cheap Generic OBD II Scan Tool

When an OBD II fault occurs in Land Rover’s Generic Engine Management System (GEMS ), the Malfunction Indicator Lamp (MIL ) is illuminated.
GEMS Diagnostic Trouble Codes (DTC ) are stored in the Engine Control Module (ECM ) and may be retrieved by connecting a suitable diagnostic reader .
DTC’s can only be Extracted, Diagnosed and Cleared by the TestBook Diagnostic Unit, (now defunct) a required special tool , or an appropriate after market equivalent.
All information regarding DTC’s for this model is contained within the Land Rover TestBook Diagnostic Unit. (now obsolete) The manufacture does not provide any other information on How to Pull Codes, Trouble Code Descriptions, Diagnosis and Testing of Trouble Codes or How to Clear codes.

*Codes* are used to identify the 4 Oxygen Sensors.
A = Bank A of the engine. Cylinder #1 is located on Engine Bank A.
B = Bank B of the engine.
U = Upstream of the Catalytic Converter.
D = Downstream of the Catalytic Converter.
Example: A D = Oxygen Sensor Engine Bank A, Downstream of Catalytic Converter.

Land Rover: Most Common OBD2 Code Chart

P0101 Mass Air Flow Sensor Signal Error Fault

P0102 Mass Air Flow Sensor Low Out of Range Fault

P0103 Mass Air Flow Sensor High Out of Range Fault

P0111 Air Temperature Sensor Signal Error Fault

P0112 Air Temperature Sensor Low Out of Range Fault

P0113 Air Temperature Sensor High Out of Range Fault

P0116 Engine Coolant Temperature Sensor Falling Temp Fault

P0117 Engine Coolant Temperature Sensor Low Out of Range Fault

P0118 Engine Coolant Temperature Sensor High Out of Range Fault

P0121 Throttle Position Sensor Output Signal Error Fault

P0122 Throttle Position Sensor Low Out of Range Fault

P0123 Throttle Position Sensor High Out of Range Fault

P0125 Engine Coolant Temp Sensor Warm Up Fault

P0130 Oxygen Sensor Cycle Fault *Codes* A U

P0131 Oxygen Sensor Low Voltage *Codes* A U

P0132 Oxygen Sensor High Voltage *Codes* A U

P0133 Oxygen Sensor Slow Response *Codes* A U

P0136 Oxygen Sensor Cycle Fault *Codes* A D

P0137 Oxygen Sensor Low Voltage *Codes* A D

P0138 Oxygen Sensor High Voltage *Codes* A D

P0139 Oxygen Sensor Slow Response *Codes* A D

P0150 Oxygen Sensor Cycle Fault *Codes* B U

P0151 Oxygen Sensor Low Voltage *Codes* B U

P0152 Oxygen Sensor High Voltage *Codes* B U

P0153 Oxygen Sensor Slow Response *Codes* B U

P0156 Oxygen Sensor Cycle Fault *Codes* B D

P0157 Oxygen Sensor Low Voltage *Codes* B D

P0158 Oxygen Sensor High Voltage *Codes* B D

P0159 Oxygen Sensor Slow Response *Codes* B D

P0171 Oxygen Sensor System Too Lean Fault Bank A

P0172 Oxygen Sensor System Too Rich Fault Bank A

P0174 Oxygen Sensor System Too Lean Fault Bank B

P0175 Oxygen Sensor System Too Rich Fault Bank B

P0181 Fuel Temperature Sensor Signal Error Fault

P0182 Fuel Temperature Sensor Low Out of Range Fault

P0183 Fuel Temperature Sensor High Out of Range Fault

P0201 Injector 1 Circuit Fault

P0202 Injector 2 Circuit Fault

P0203 Injector 3 Circuit Fault

P0204 Injector 4 Circuit Fault

P0205 Injector 5 Circuit Fault

P0206 Injector 6 Circuit Fault

P0207 Injector 7 Circuit Fault

P0208 Injector 8 Circuit Fault

P0300 Misfire On Multiple Cylinder

P0301 Misfire Cylinder 1

P03O2 Misfire Cylinder 2

P03O3 Misfire Cylinder 3

P0304 Misfire Cylinder 4

P0305 Misfire Cylinder 5

P0306 Misfire Cylinder 6

P0307 Misfire Cylinder 7

P0308 Misfire Cylinder 8

P0326 Continuous Knock Fault Bank A

P0327 Background Noise Low Fault Bank A

P0328 Background Noise High Fault Bank A

P0331 Continuous Knock Fault Bank B

P0332 Background Noise Low Fault Bank B

P0333 Background Noise High Fault Bank B

P0335 Crankshaft Position Sensor Signal Error Fault

P0336 Crankshaft Position Sensor Out of Range Fault

P0340 Camshaft Position Sensor Signal Error Fault

P0420 Catalyst Efficiency Low Fault Bank A

P0430 Catalyst Efficiency Low Fault Bank B

P0441 Evap Purge Valve Incorrect Flow Fault

P0442 Evap System Small Leak Detected Fault

P0443 Evap Purge Valve Open or Short Circuit Fault

P0451 Fuel Tank Pressure Sensor Signal Error Fault

P0452 Fuel Tank Pressure Sensor Low out of Range Fault

P0453 Fuel Tank Pressure Sensor High Out of Range Fault

P0461 Fuel Tank Level Measurement Not Valid Fault

P0500 Vehicle Speed Sensor Signal Error Fault

P0506 Idle Speed Control Engine Speed Low Fault

P0507 Idle Speed Control Engine Speed High Fault

P0560 Battery Voltage Below Minimum Fault

P0562 Measurement Circuit OK Battery Voltage Low Fault

P0563 Battery Voltage Above Maximum Fault

P0605 ECM Self Test Fault

P1130 Oxygen Sensor Fuel Trim at Limit *Codes* A U

P1131 Oxygen Sensor Engine Lean *Codes* A U

P1132 Oxygen Sensor Engine Rich *Codes* A U

P1137 Oxygen Sensor Engine Lean *Codes* A D

P1138 Oxygen Sensor Engine Rich *Codes* A D

P1150 Oxygen Sensor Fuel Trim at Limit *Codes* B U

P1151 Oxygen Sensor Engine Lean *Codes* B U

P1152 Oxygen Sensor Engine Rich *Codes* B U

P1157 Oxygen Sensor Engine Lean *Codes* B D

P1158 Oxygen Sensor Engine Rich *Codes* B D

P1171 Oxygen Sensor System Too Lean Fault Banks A & B

P1172 Oxygen Sensor System Too Rich Fault Banks A & B

P1176 Maximum Positive FMFR Correction Fault

P1177 Maximum Negative FMFR Correction Fault

P1178 Maximum Positive AMFR Correction Fault

P1179 Maximum Negative AMFR Correction Fault

P1185 Oxygen Sensor Heater Circuit Open Upstream

P1186 Oxygen Sensor Heater Circuit Short Upstream

P1187 Oxygen Sensor Heater Circuit Short Upstream

P1188 Oxygen Sensor Heater High Resistance Upstream

P1189 Oxygen Sensor Heater Type 1 Low Resistance Upstream

P1190 Oxygen Sensor Heater Type 2 Low Resistance Upstream

P1191 Oxygen Sensor Heater Circuit Open Downstream

P1192 Oxygen Sensor Heater Circuit Short Downstream

P1193 Oxygen Sensor Heater Circuit Open Downstream

P1194 Oxygen Sensor Heater High Resistance Downstream

P1195 Oxygen Sensor Heater Type 1 Low Resistance Downstream

P1196 Oxygen Sensor Heater Type 2 Low Resistance Downstream

P1199 Fuel Level Sensor Circuit Fault

P1201 Injector 1 Open Circuit or Ground Short Fault

P1202 Injector 2 Open Circuit or Ground Short Fault

P1203 Injector 3 Open Circuit or Ground Short Fault

P1204 Injector 4 Open Circuit or Ground Short Fault

P1205 Injector 5 Open Circuit or Ground Short Fault

P1206 Injector 6 Open Circuit or Ground Short Fault

P1207 Injector 7 Open Circuit or Ground Short Fault

P1208 Injector 8 Open Circuit or Ground Short Fault

P1313 Misfire Catalyst Damage Fault Bank A

P1314 Misfire Catalyst Damage Fault Bank B

P1315 Misfire Persistent Fault

P1316 Misfire Excessive Emissions Fault

P1317 ABS Rough Road Line Low Fault

P1318 ABS Rough Road Line High Fault

P1361 No Ignition Coil Activation Fault Coil 1

P1362 No Ignition Coil Activation Fault Coil 2

P1363 No Ignition Coil Activation Fault Coil 3

P1364 No Ignition Coil Activation Fault Coil 4

P1371 Early Ignition Coil Activation Fault Coil 1

P1372 Early Ignition Coil Activation Fault Coil 2

P1373 Early Ignition Coil Activation Fault Coil 3

P1374 Early Ignition Coil Activation Fault Coil 4

P1440 Evap System Purge Valve Stuck Open Fault

P1441 Evap System Purge Valve Flow 1 Fault

P1442 Evap System Purge Valve Blocked Fault

P1447 Evap System Purge Valve Open or Short Circuit Fault

P1448 Evap System Purge Valve Flow 2 Fault

P1508 Idle Speed Control Open Circuit Fault

P15O9 Idle Speed Control Short Circuit Fault

P1514 Neutral Drive Load Fault

P1516 Neutral Drive Gear Change Fault

P1517 Neutral Drive Cranking Fault

P1607 Malfunction Indicator Lamp Short Circuit Fault

P1608 Malfunction Indicator Lamp Open Circuit Fault

P1620 Reprogramming Code Learn Fault

P1621 Serial Data Link Dead Fault

P1622 Repeated Wrong ECM Security Code Fault

P1623 ECM Security Code Fault

P1701 Transfer Box Line Fault

P1703 Transfer Box Line Open Circuit Fault

P1708 Transfer Box Line Short Circuit Fault

P1775 Gearbox Fault

P1776 Gearbox Ignition Retard Request Timeout Fault

P1777 Gearbox Ignition Retard Request Line Fault