hey i am converting to obd1 from obd0 and want to just cut the old harness and splice in the obd1 connectors for the ecu the only thing is i cannot find a pin out diagram or anything, if anyone knows of one that would be helpful.

also i have a sensor that is from the obd0 harness and on the 0bd1 motor there is no spot for it, but the connector is still there, i do not know what kind of sensor it is it is located on the back of the block right near the oil filter i think that it is the knock sensor from the obd0 motor which is that plug and sensor that have no where to go on the motor,

 

Hope this helps


If you want to convert your obd0 Honda (generally pre-92) to obd1 standard,
follow the diagram/pinout.
Obd0 to Obd1 wiring harness conversion pinouts:
53 to 45 pins. + 4

A - 18
B - 11
+--------+------------+--------------+----------------------------------+------------------
| pin_id | wire_color | pin_function | pin_name | 4G OBD0 (PR3 pin)
+--------+------------+--------------+----------------------------------+------------------
| A1 | BRN | INJ1 | INJ1 | -> A1
| A2 | YEL | INJ4 | INJ4 | -> A7
| A3 | RED | INJ2 | INJ2 | -> A3
| A4 | GRN/YEL | VTS | VTEC solenoid | -> ADD -> vtec selenoid
| A5 | BLU | INJ3 | INJ3 | -> A5
| A6 | ORN/BLK | PO2SHTC | O2 sensor (heating element) | -> ADD [o2 heater control ->blk (under wht wire)]
| A7 | GRN/BLU | FLR1 | fuel pump (main relay) | -> A12
| A9 | BLK/BLU | IACV | IAC valve | -> A11
| A12 | GRN | FANC | engine coolant temp switch | -> B4
| A13 | GRN/ORN | MIL | MIL (check engine light) | -> B6
| A15 | BLK/RED | ACC | (a/c compressor clutch) | -> B3
| A16 | WHT/GRN | ALT C | alternator | -> B5
| A20 | RED | PCS | EVAP purge control solenoid | -> A6
| A21 | YEL/GRN | ICM | ICM | -> B15
| A23 | BLK | PG1 | ground *(main relay ground) | -> A2
| A24 | BLK | PG2 | ground *(main relay ground) | -> A4
| A25 | YEL/BLK | IGP2 | to main relay and to gound for o | -> A13 [splice for o2 -> blk (under grn)]
| A26 | BRN/BLK | LG1 | gound | -> A18
| B1 | YEL/BLK | IGP2 | to pin A25 | -> A15
| B2 | BRN/BLK | LG2 | ground to shields for CYP & TDC | -> A16
| B5 | BLU/RED | ACS | a/c switch | -> B8
| B9 | BLU/WHT | | starter signal | -> B13
| B10 | ORN | VSS | vehicle speed sensor | -> B16
| B11 | ORN | CYP P | CYP -P | -> B10
| B12 | WHT | CYP M | CYP -M | -> B12
| B13 | ORN/BLU | TDC P | TDC -P | -> C3
| B14 | WHT/BLU | TDC M | TDC -M | -> C4
| B15 | BLU/GRN | CKP P | CKP -P | -> C1
| B16 | BLU/YEL | CKP M | CKP -M | -> C2
| D1 | WHT/BLU | VBU | Back Up Power | -> B1
| D2 | GRN/WHT | BKSW | brake switch | -> C10
| D3 | | KS | Knock Sensor | -> ADD -> Knock sensor
| D4 | BRN/WHT | SCS | service check connector | -> mil [toggle switch with ground]
| D6 | BLU/BLK | VTM | VTEC pressure switch | -> ADD -> vtec pressure switch
| D9 | WHT/RED | ALT F | alternator | -> B14
| D10 | GRN/RED | ELD | electric load detector | -> B19
| D11 | RED/BLK | TPS | TPS Signal | -> C7
| D13 | RED/WHT | ECT | ECT sensor | -> C6
| D14 | WHT/RED | PHO2S | O2 sensor | -> C16 [splice for o2 -> wht]
| D15 | RED/YEL | IAT | IAT sensor | -> C5
| D17 | WHT/YEL | MAP | Map Signal | -> C11
| D19 | YEL/WHT | VCC1 | MAP 5V | -> C15
| D20 | YEL/BLU | VCC2 | TPS 5V | -> C13
| D21 | GRN/WHT | SG1 | MAP GND | -> C14
| D22 | GRN/BLU | SG2 | TPS GND | -> C12 [splice for o2 -> grn]
+--------+------------+--------------+----------------------------------+