can anyone help me locate ecu diagnostic plug on a 99 accord and also a list of codes

 

The OBD-2 port is under the driver's dashboard, way over to the left. Sorta above where your left knee would be.

CEL DTCs...
P0107 (3)MAP circuit low input
P0108 (3)MAP circuit high input
P0112 (10)IAT intake air temp. low input
P0113 (10)IAT intake air temp. high input
P0116 (86)ECT coolant temp. range/perf problem
P0117 (6)ECT circuit low input
P0118 (6)ECT circuit high input
P0122 (7)TPS circuit low input
P0123 (7)TPS circuit high input
P0131 (1)pri.HO2S low voltage (P0130)
P0132 (1)pri.HO2S high voltage (P0130)
P0133 (61)pri.HO2S slow response
P0135 (41)pri.HO2S heater circuit
P0137 (63)sec.HO2S low voltage (P0136)
P0138 (63)sec.HO2S high voltage (P0136)
P0139 (63)sec.HO2S slow response (P0136)
P0141 (65)sec.HO2S heater circuit
P0171 (45)system too lean (P0170)
P0172 (45)system too rich (P0170)
P0300random misfire (P1399)
P0301 (71)cyl.1 misfire (P1399)
P0302 (72)cyl.2 misfire (P1399)
P0303 (73)cyl.3 misfire (P1399)
P0304 (74)cyl.4 misfire (P1399)
P0325 (23)KS knock sensor circuit problem
P0335 (4)crankshaft position sensor low input
P0336 (4)crankshaft position sensor range/performance
P0401 (80)EGR low flow rate
P0420 (67)catalyst low efficiency
P0452 (91)fuel tank pressure sensor low input (P0450)
P0453 (91)fuel tank pressure sensor high input (P0450)
P0500 (17)VSS (MT only)
P0505 (14)Idle Control System malfunction
P0715 (70)AT; (15) no shift 2-3; speedo; L-U-Clutch no engage
P0720 (70)AT; (9) no shift 2-3; L-U-Clutch no engage
P0725 (70)AT; Engine Speed Input Circuit Malfunction??
P0730 (70)AT; (41) no shift 1-2,1-2-3,1-3-4,2-3-4; stuck in 4th
P0740 (70)AT; (40) L-U-Clutch no engage
P0753 (70)AT; (7) stuck in 4th
P0758 (70)AT; (8) stuck in 4th
P0763 (70)AT; (22) stuck in 4th
P1106 (13)Baro.P circ.range / perf.prob.
P1107 (13)Baro.P low input
P1108 (13)Baro.P high input
P1121 (7)Throttle Position lower than expected
P1122 (7)Throttle Position higher than expected
P1128 (5)Man.Press. lower than expected
P1129 (5)Man.Press. higher than expected
(several for F23A4 only)
P1253 (21)VTEC system malfunction (P1257)
P1257 (22)VTEC system malfunction (P1257)
P1258 (22)VTEC system malfunction (P1257)
P1259 (22)VTEC system malfunction (P1257)
P1297 (20)ELD low voltage
P1298 (20)ELD high voltage
P1359 (8)Crank.pos/TDC connector disconnected
P1361 (8)TDC sensor intermittent
P1362 (8)TDC sensor no signal
P1381 (9)CYP sensor intermittent
P1382 (9)CYP sensor no signal
P1456 (90)EVAP leak - fuel tank system
P1457 (90)EVAP leak - control canister system
P1491 (12)EGR valve lift insufficient
P1498 (12)EGR valve lift sensor high voltage
P1519 (14)IACV circuit failure
P1607 (-)ECM/PCM internal circuit failure A
P1705AT; (5) no shift except 2-3; L-U-Clutch no engage
P1706AT; (6) no specific symptom
P1738AT; (25) no specific symptom
P1739AT; (26) no specific symptom
P1753 (70)AT; (1) L-U-Clutch no engage/disengage; stuck in 4th
P1768AT; (16) stuck in 4th; L-U-Clutch no engage
P1773AT; (23) stuck in 4th; L-U-Clutch no engage
P1791AT; Vehicle Speed Sensor (VSS) Range/Performance Problem

 

Thanks to Jim for providing the codes for you ,, But you should do a search first ..
here is a link,, it takes a lot less space in the forum than all the codes Jim provided

http://www.troublecodes.net/honda/