182:
24:
243:
When the ignition is first turned on, the ECU energizes a relay that runs the fuel pump for a short time to pressurize the fuel rail. Once the starter motor begins to turn the engine, the ECU gets a 12VDC signal that causes it to run the fuel pump again, and energize the fuel injectors. For the next
401:
The ECU interfaces with the rest of the system via a 40-pin connector. When observing the connector on the ECU box itself, with the thumb latch on the left, the numbering for the connector's pins starts at 1 in the lower left-hand corner. The pin numbering continues to the right, then in an S-shape
172:
The 14CUX was the final iteration of the system, and featured upgraded injectors and (for some markets) an external diagnostic display. It also introduced the use of a "tune resistor", which is an external resistor that plugs into the harness and is sensed by the ECU to select one of five different
334:. As a result, the diagnostics information collected by the 14CUX is not accessible via an OBD-II-compliant interface. In lieu of an industry-standard diagnostic interface, the 14CUX is able to communicate over a serial link at non-standard voltage levels and baud rate. The reference clock for the
289:
speed and engine load) are used to index into a two-dimensional matrix of numeric values known as the "fuel map". The value read from the map is offset by other environmental factors (such as coolant temperature). This corrected value is then used to meter fuel by pulse-width modulating the fuel
350:
down from 12VDC from the vehicle's battery.) Because of this maintainer voltage, the ECU is always drawing a small amount of current. Fault codes can be cleared by disconnecting the battery for a short period of time. Diagnostic trouble codes can be retrieved from the ECU via a small electronic
209:
efforts. The 14CUX determines fueling values for each bank of the V8 separately, which requires the use of two dedicated timer outputs for independent control of the fuel injectors. This requirement helped to drive the selection of the MC6803U4 part, which has three timer outputs available (in
338:
runs at 1 MHz and the clock divisor is set to 128, which produces a data rate of 7812.5 baud. The serial interface allows reading and writing arbitrary memory locations via a simple software protocol. Because the value from a given sensor is always stored at the same location in
220:(depending on the revision of the ECU), which is soldered in place on most PRC units and socketed in some late PRC units as well as AMR units. Only half of the 32KB PROM space is used, so the code/data image appears twice, duplicated in the upper half.
393:. This was done in part due to the requirement for OBD-II in the United States market. Some automakers whose products were not exported to North America (such as TVR) continued to use the 14CUX until the later discontinuation of the Rover V8 engine.
281:
The intake air mass is measured with a "hot-wire" mass airflow sensor: drawn in by intake manifold vacuum, air moves past an electrically heated wire filament, and the degree to which the filament is cooled indicates the mass of the airstream.
317:
Above a certain engine speed or throttle position, the ECU switches to "open-loop" mode; the inputs from the exhaust lambda sensors are ignored and the mixture is enriched beyond stoichiometric for higher power and decreased engine wear.
321:
In addition to engine speed and load conditions triggering open-loop mode, the selection of the fuel map also may force this mode. For certain fuel maps, the 14CUX firmware fuels in open-loop mode under all running conditions.
389:
For model year 1996, Land Rover chose to discontinue use of the 14CUX in its products and instead used GEMS ("Generic Engine
Management System"), which had been developed jointly by Lucas and
301:
may contain up to five fuel maps, which allowed a single ROM image to contain maps for multiple target markets. In some markets, the active map is selectable by placing an external tune
158:
requirements. The design of the 13CU also deviated from the original L-Jetronic design in that it used a hot-wire air mass sensor rather than the
Jetronic's mechanical flap sensor.
355:
that together show a single two-digit fault code. When connected to the 14CUX wiring harness, the ECU detects its presence and reconfigures the RDATA and TDATA lines to work as an
346:
The 14CUX is capable of storing diagnostic trouble codes in a 32-byte segment of its internal memory that is maintained (even while vehicle ignition is off) by applying 5VDC (
383:. In the TVR applications, engines as large as 5.0L were offered; these larger displacements required the development of new fuel maps for the engine to run properly.
330:
The design of the 14CUX was done well in advance of the requirement (for the 1996 model year) that all passenger vehicles sold in the United States support
244:
several seconds, the injector pulse width is wider than normal to provide sufficient fuel for starting. Idle control is performed by adjusting a
213:
Minor design updates were made to the ECU through its life, with the earlier units given the part-number prefix "PRC" and the later units "AMR".
1050:
161:
The 13CU was further developed into the 14CU, which had (among other changes) an ECU that was more physically compact. The 14CU was used in
252:. When the ignition is switched off, the ECU winds the bypass valve fully open to provide enough air the next time the engine is started.
1090:
155:
111:
vehicles between 1990 and 1995. The system was also paired with the Rover V8 by a number of low-volume manufacturers such as
255:
To determine the amount of fuel required by the engine, the ECU reads a number of sensors measuring the following factors:
298:
72:
1074:
130:
The system is also sometimes referred to as the "Rover Hot-Wire" or "Hitachi Hot-Wire", in reference to the style of
1095:
233:
352:
368:
340:
331:
124:
372:
206:
190:
166:
116:
386:
Between 1990 and 1993, Ginetta produced the G33 roadster, which used the 3.9L Rover V8 and 14CUX.
169:
in 1989. Both the 13CU and 14CU were designed for use with only the 3.5L version of the Rover V8.
1046:
347:
147:
131:
100:
37:
181:
104:
305:
on a particular pin of the ECU. This external map selection was disabled in the code for
1015:
249:
236:. On 14CUX-equipped vehicles, the spark control is done mechanically with the use of a
198:
96:
1084:
306:
291:
245:
202:
162:
216:
The code and data used by the microprocessor is stored in either a 27C128 or 27C256
1069:
380:
376:
120:
294:, the air/fuel ratio can be monitored and controlled for the banks independently.
237:
286:
108:
23:
351:
display referred to as the "Fault Code
Display Unit". This unit contains two
290:
injectors. Because each bank of the V8 feeds an exhaust line with its own
302:
229:
228:
In contrast to more modern engine management systems, the 14CUX controls
194:
151:
78:
135:
154:
system and adding an electronic diagnostics capability to comply with
343:, these sensor values can be read if the memory location is known.
390:
217:
180:
146:
In the mid-1980s, Lucas developed the 13CU system by revising the
205:. The processor is mislabelled in the ECU, possibly to deter any
1016:"Service and Troubleshoot Rover 14CUX Electronic Fuel Injection"
335:
375:, and Range Rover, the 14CUX was used with the Rover V8 in the
356:
112:
210:
contrast to the single timer output on the standard 6803.)
201:, which is an uncommon variant of the otherwise ubiquitous
1070:
Reverse-engineered 14CUX ECU and serial port information
490:
Some NAS vehicles do not have a pin at this position
504:To main connector (0-12V six times per revolution)
185:
A Rover V8 3.9L engine fitted with the 14CUX system
67:
59:
51:
43:
33:
770:Ground side of coolant, fuel, MAP, and TP sensors
1043:How to Power Tune Rover V8 for Road & Track
28:Main printed circuit board of the Lucas 14CUX
8:
16:
15:
476:O2 sensor heater return (Lambda ground)
404:
134:it uses (and the sensor's manufacturer,
992:
47:Electronic automobile engine management
193:(ECU) of the 14CUX system is run by a
7:
963:Engine speed (ignition spark input)
406:Pinout of the 40-pin ECU connector
274:Exhaust oxygen content (narrowband)
248:-driven bypass valve in the intake
232:delivery only; it does not control
879:A/C compressor clutch relay output
14:
1075:Ginetta G33 Fuel Injection System
966:Harness includes 6.8KΩ resistor
910:0.3 to 0.6 VDC with ignition on
686:Input (+12VDC when ignition on)
402:through the two other pin rows.
22:
1014:Jacobson, Curtis (April 2007).
711:Air conditioner compressor load
672:Input from 5-pin TTS connector
644:Output to fuel pump relay coil
630:Input (+12VDC always applied)
546:Output to 5-pin TTS connector
397:Main connector pin assignments
367:In addition to the Land Rover
309:specification (NAS) vehicles.
156:California Air Resources Board
95:) is an automotive electronic
91:(sometimes referred to as the
1:
708:yellow/black to yellow/green
683:Fuel pump and inertia switch
924:Tall green unit (AMR 3678)
893:Transmission neutral switch
865:Fuel temperature thermistor
848:black/green or black/yellow
571:Even (right) bank injectors
1112:
896:Input from main connector
868:Input from gray connector
588:Output to main relay coil
532:Input from main connector
515:Coolant temperature sensor
1001:13/14CU AND 14CUX SYSTEMS
960:white/black or white/blue
952:Output to main connector
840:Output to main connector
680:white/gray or white/green
599:Odd (left) bank injectors
560:Output to main connector
21:
700:Swings 0.29 to 5.00 VDC
459:Throttle position sensor
379:and its sister car, the
627:Ignition and main relay
498:yellow (or yellow/pink)
1091:Fuel injection systems
725:MAF sensor (idle trim)
697:Throttle potentiometer
669:Diagnostic serial port
543:Diagnostic serial port
353:seven-segment displays
186:
173:sets of fueling data.
1045:. Veloce Publishing.
1041:Hammill, Des (2003).
359:link to this device.
184:
99:system developed by
921:Condenser fan timer
753:Right lambda sensor
655:Purge control valve
554:black/yellow or red
529:Heated front screen
518:To brown connector
407:
262:Coolant temperature
207:reverse engineering
191:engine control unit
18:
949:Fault display data
837:Fault display data
739:Left lambda sensor
445:MAF and main relay
420:Description/Notes
405:
187:
103:and fitted to the
1096:Engine components
1052:978-1-903706-17-6
984:
983:
826:48-58Ω to pin 28
812:48-58Ω to pin 29
557:EFI warning light
540:white/light green
434:48-58Ω to pin 26
268:Throttle position
85:
84:
63:Lucas 13CU / 14CU
1103:
1057:
1056:
1038:
1032:
1031:
1029:
1027:
1011:
1005:
1004:
997:
823:Air bypass valve
809:Air bypass valve
784:48-58Ω to pin 1
781:Air bypass valve
501:Speed transducer
431:Air bypass valve
408:
271:Fuel temperature
101:Lucas Industries
38:Lucas Industries
26:
19:
1111:
1110:
1106:
1105:
1104:
1102:
1101:
1100:
1081:
1080:
1077:(www.g33.co.uk)
1066:
1061:
1060:
1053:
1040:
1039:
1035:
1025:
1023:
1013:
1012:
1008:
999:
998:
994:
989:
935:(no connection)
851:Diagnostic plug
641:Fuel pump relay
448:Input (+12VDC)
399:
365:
328:
315:
259:Intake air mass
226:
197:MC6803U4 8-bit
179:
144:
105:Rover V8 engine
76:
29:
12:
11:
5:
1109:
1107:
1099:
1098:
1093:
1083:
1082:
1079:
1078:
1072:
1065:
1064:External links
1062:
1059:
1058:
1051:
1033:
1020:britishv8.org/
1006:
991:
990:
988:
985:
982:
981:
978:
975:
972:
968:
967:
964:
961:
958:
954:
953:
950:
947:
944:
940:
939:
936:
933:
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926:
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922:
919:
916:
912:
911:
908:
905:
902:
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883:
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869:
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849:
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835:
832:
828:
827:
824:
821:
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813:
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807:
804:
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799:
796:
793:
790:
786:
785:
782:
779:
776:
772:
771:
768:
765:
762:
758:
757:
756:Blue shielded
754:
751:
748:
744:
743:
742:Blue shielded
740:
737:
734:
730:
729:
726:
723:
720:
716:
715:
712:
709:
706:
702:
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664:
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628:
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583:
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572:
569:
566:
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541:
538:
534:
533:
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516:
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510:
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505:
502:
499:
496:
492:
491:
488:
485:
482:
478:
477:
474:
471:
468:
464:
463:
462:5kΩ to pin 25
460:
457:
454:
450:
449:
446:
443:
440:
436:
435:
432:
429:
426:
422:
421:
418:
415:
412:
398:
395:
364:
361:
327:
324:
314:
311:
307:North American
279:
278:
275:
272:
269:
266:
263:
260:
234:spark ignition
225:
222:
199:microprocessor
178:
175:
143:
140:
132:airflow sensor
97:fuel injection
83:
82:
69:
65:
64:
61:
57:
56:
53:
49:
48:
45:
41:
40:
35:
31:
30:
27:
13:
10:
9:
6:
4:
3:
2:
1108:
1097:
1094:
1092:
1089:
1088:
1086:
1076:
1073:
1071:
1068:
1067:
1063:
1054:
1048:
1044:
1037:
1034:
1021:
1017:
1010:
1007:
1003:. Land Rover.
1002:
996:
993:
986:
979:
976:
973:
970:
969:
965:
962:
959:
956:
955:
951:
948:
945:
942:
941:
937:
934:
931:
928:
927:
923:
920:
917:
914:
913:
909:
906:
903:
900:
899:
895:
892:
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886:
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881:
878:
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871:
867:
864:
861:
858:
857:
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844:
843:
839:
836:
833:
830:
829:
825:
822:
819:
816:
815:
811:
808:
805:
802:
801:
797:
795:Signal ground
794:
791:
788:
787:
783:
780:
777:
774:
773:
769:
767:Sensor ground
766:
763:
760:
759:
755:
752:
749:
746:
745:
741:
738:
735:
732:
731:
727:
724:
721:
718:
717:
713:
710:
707:
704:
703:
699:
696:
693:
690:
689:
685:
682:
679:
676:
675:
671:
668:
665:
662:
661:
657:
654:
651:
648:
647:
643:
640:
637:
634:
633:
629:
626:
623:
620:
619:
615:
612:
609:
606:
605:
601:
598:
595:
592:
591:
587:
584:
581:
578:
577:
573:
570:
567:
564:
563:
559:
556:
553:
550:
549:
545:
542:
539:
536:
535:
531:
528:
526:purple/yellow
525:
522:
521:
517:
514:
511:
508:
507:
503:
500:
497:
494:
493:
489:
487:Tune resistor
486:
483:
480:
479:
475:
472:
469:
466:
465:
461:
458:
455:
452:
451:
447:
444:
441:
438:
437:
433:
430:
427:
424:
423:
419:
416:
413:
410:
409:
403:
396:
394:
392:
387:
384:
382:
378:
374:
370:
362:
360:
358:
354:
349:
344:
342:
337:
333:
325:
323:
319:
312:
310:
308:
304:
300:
295:
293:
292:oxygen sensor
288:
285:Two factors (
283:
276:
273:
270:
267:
264:
261:
258:
257:
256:
253:
251:
247:
246:stepper-motor
241:
239:
235:
231:
223:
221:
219:
214:
211:
208:
204:
200:
196:
192:
183:
176:
174:
170:
168:
164:
159:
157:
153:
149:
141:
139:
137:
133:
128:
126:
122:
118:
114:
110:
106:
102:
98:
94:
90:
80:
74:
70:
66:
62:
58:
54:
50:
46:
42:
39:
36:
32:
25:
20:
1042:
1036:
1024:. Retrieved
1022:. British V8
1019:
1009:
1000:
995:
890:orange/black
568:yellow/white
442:brown/orange
400:
388:
385:
377:TVR Griffith
366:
363:Applications
345:
329:
320:
316:
296:
284:
280:
265:Engine speed
254:
242:
227:
215:
212:
188:
171:
167:Range Rovers
160:
145:
129:
92:
88:
86:
71:Lucas/SAGEM
52:Release date
34:Manufacturer
918:black/green
778:green/white
652:gray/yellow
638:blue/purple
596:yellow/blue
326:Diagnostics
238:distributor
93:Rover 14CUX
89:Lucas 14CUX
60:Predecessor
17:Lucas 14CUX
1085:Categories
987:References
977:ECM ground
946:brown/pink
907:MAF sensor
904:blue/green
876:black/gray
862:gray/white
792:black/gray
666:white/pink
613:ECM ground
585:Main relay
512:green/blue
484:gray/black
297:The 14CUX
287:crankshaft
277:Road speed
109:Land Rover
1026:March 13,
806:blue/gray
764:red/black
428:red/green
369:Discovery
348:regulated
313:Open loop
68:Successor
722:blue/red
582:blue/red
381:Chimaera
373:Defender
303:resistor
224:Function
195:Motorola
177:Hardware
165:-market
152:Jetronic
79:Motronic
658:Output
602:Output
574:Output
142:History
136:Hitachi
121:Ginetta
1049:
854:Input
820:orange
714:Input
473:Ground
456:yellow
332:OBD-II
250:plenum
125:Morgan
123:, and
117:Marcos
77:Bosch
974:black
932:(n/a)
624:brown
610:black
470:black
414:Color
391:SAGEM
218:EPROM
148:Bosch
81:ML2.1
1047:ISBN
1028:2014
834:pink
417:Name
336:UART
299:PROM
230:fuel
203:6803
189:The
87:The
73:GEMS
55:1990
44:Type
971:40
957:39
943:38
929:37
915:36
901:35
887:34
873:33
859:32
845:31
831:30
817:29
803:28
789:27
775:26
761:25
750:unk
747:24
736:unk
733:23
719:22
705:21
694:red
691:20
677:19
663:18
649:17
635:16
621:15
607:14
593:13
579:12
565:11
551:10
411:Pin
357:I2C
341:RAM
138:).
113:TVR
107:in
1087::
1018:.
980:-
938:-
882:-
798:-
728:-
616:-
537:9
523:8
509:7
495:6
481:5
467:4
453:3
439:2
425:1
371:,
240:.
163:US
150:L-
127:.
119:,
115:,
1055:.
1030:.
75:8
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