P72
Library.P72 · r1.18 · · 91crxsi
ROM addresses and their functions specific to the stock Honda P72 used in:
Picture of OBD1 P72 (thanks Katman): scan
To add an address, click Edit below, find where your Hex Offset address is, and then add your new entry like so:
"|''location''|''length in bytes''|''description''|''notes''|"
Note: Please do not add info specific to specialized ROMs such as Uber P72 and Hi Res P72.
*Some of these addresses were determined by comparing dasms of 273 vs. 203 and correlating known 203 addresses with the ones found in the 273.
RAM
| Location | Bytes | Description | Notes |
| 00bb | 1 | raw MAP | set at 0844 |
| 00bf | 1 | adjusted MAP | more info... |
| 00C3 | 1 | Current RPM | also copied to 236h (look at 0816h) |
| 00C4 | 2 | Current RPM | |
| 00CC | 1 | VSS Sensor | km/h |
| 00D1 | 1 | Current TPS | Throttle Position (see Tps Sensor) |
| 00D4 | 1 | TP Sensor | |
| 00D5 | 1 | TPS Delta | |
| 00D7 | 1 | Input into ADCR5 | not connected to a sensor on USDM P72 |
| 00D8 | 1 | IAT Sensor | |
| 00D9 | 1 | ECT Sensor | |
| 00DA | 1 | O2 Sensor | |
| 011a | 1 | CEL byte 1 | |
| 011b | 1 | CEL byte 2 | |
| 011c | 1 | CEL byte 3 | |
| 011d | 1 | CEL byte 4 | |
| 011E.3 | 1b | Auto/Manual config bit | |
| 0127.1 | 1b | VTEC bit | |
| 0131.0 | 1b | set if speed > 15 kph, cleared if speed < 10 kph | used to determine if VTEC should be on |
| 0131.1 | 1b | set when RPM is above VTEC switchover RPM | has hysteresis, related to VTEC logic |
| 0131.2 | 1b | set when RPM is above some level | has hysteresis, related to VTEC logic |
| 0131.6 | 1b | similar to 0131.2, but at a different level | not related to VTEC logic |
| 0131.7 | 1b | similar to 0131.6, but looks at MAP, not RPM | not related to VTEC logic |
| 0192 | Rev cut limit | ||
| 0194 | Rev resume limit | ||
| 01D2 | 1 | Column of Fuel/Ignition Map | |
| 01D8 | 1 | Low Cam Row | |
| 01D9 | 1 | High Cam Row | |
| 0210.3 | 1b | Power Steering Pressure(PSP) switch input | If pin B8 (PSP) is grounded, 0x0210.3 will read 0 else it will read 1 |
| 0211.2 | 1b | AC switch | more info... |
| 0212.2 | 1b | Indicates MAP problem | |
| 0212.4 | 1b | Indicates other MAP problem | |
| 0212.6 | 1b | Indicates TPS problem | |
| 0216.4 | 1b | Vtec Enable Flag | |
| 0216.6 | 1b | Holds 02 Sensor Heater Enable Flag | |
| 0219.3 | 1b | ????????? | |
| 0227.4 | 1b | PA Sensor Enable Flag | |
| 0227.6 | 1b | Knock Sensor Enable Flag | |
| 022d.1 | 1b | VTEC VSS Check Enable Flag | |
| 0236 | 1 | Current RPM in 8bit form (IAB Control @ 4393h routine) | |
| 0244 | 1 | Knock Retard | |
| 0246 | 1 | Ignition Advance | |
| 0257 | 1 | controls ADC MUX Channel | 0 thru 7 |
| 025A | 2 | Current target idle RPM | function of ECT and tbl_5ba7 |
| 0356.1 | 1b | Serial comm mode | 1 for 9470 UART mode, 0 for 62500 9-bit mode |
| 03A0 | 2 | Injector Duration | |
| 03CD | 1 | BARO Sensor | |
| 03D2 | 1 | ELD? | (ADC input 1) |
| 0f00 | 1 | 82C55 Port A | inputs |
| 1f00 | 1 | 82C55 Port B | outputs |
| 2f00 | 1 | 82C55 Port C | outputs |
| 3f00 | 1 | 82C55 Command Register | |
| 4700 | 1 | memory-mapped digital inputs | bit values modified and copied to 0119 and 0211, includes feedback from A/C switch, VTEC solenoids and others |
| P0.0 | 1b | A/C Clutch Output | |
| P0.1 | 1b | Purge Canister Output | |
| P0.5 | 1b | IAB Output | previously thought to be P4.3 |
| P1.0 | 1b | Left VTEC Transistor Output (IC14) | |
| P1.1 | 1b | Right VTEC Transistor Output (IC13) | |
ROM
| Location | Bytes | Description | Notes |
| 0630 | 3 | Injector test bypass #1 | Disable J label_063D(checked)03 3D 06 |
| 0B85 | 2 | Low Speed Ignition Map Config, Column Size | more info... |
| 0B87 | 2 | Low Speed Ignition Map Config, Row Size | more info... |
| 0B95 | 3 | Low Speed Ignition Map at this jump | more info... |
| 0BA1 | 2 | High Speed Ignition Map Config, Row Size | more info... |
| 0BA9 | 2 | High Speed Ignition Map at this jump | more info... |
| 11BA | 1 | VTEC On/Off Logic | |
| 120E | 1 | VTEC Coolant Temp Check | (enable=44/disable=FF) |
| 1520 | 3 | Injector test bypass #2 | Disable J label_153A(ckecked)03 3A 15 |
| 2315 | 3 | O2 Heater Jump Routine | Change to "03 50 23" to disable O2 heater |
| 2D43 | 2 | Rolling Target Idle | RPM = 1875000/(word at 0x2D43) |
| 2D58 | 2 | Cold Target Idle | RPM = 1875000/(word at 0x2D58) |
| 2D81 | 2 | Warm Target Idle | RPM = 1875000/(word at 0x2D81) |
| 3BE1 | 3 | VTP Sensor Disable | Change to "03 FF 3B" to disable VTP sensor check (tested!) |
| 43A2 | 1 | IAB on | IAB open 8bit RPM (byte at 0x43A2) |
| 439D | 1 | IAB off | IAB close 8bit RPM (byte at 0x439D) |
| 5466 | 1 | Vtec Enable | (enable=FF/disable=00)(Needs Testing?) |
| 5467 | 1 | Knock Sensor | (enable=FF/disable=00) |
| 5468 | 1 | O2 Heater | (enable=FF/disable=00)(Needs Testing?) |
| 5469 | 1 | PA Sensor | (enable=FF/disable=00) |
| 546D | 1 | maybe injector test? | |
| 547D | 1 | VTEC VSS Check | (enable=00/disable=FF) More info: Disable Vtec VSSCheck P72 |
| 547E | 1 | Debug Mode | (0xFF enables, 0x00 disables) More info: P72 Debug Mode |
| 5488 | 1 | Serial Mode | (FFh Enables UART Norm 9470bps) |
| 5489 | 1 | Iab control | (0xFF enables, 0x00 disables) |
| 58DA | 1 | Rev Resume #1 | RPM = 1875000/(byte at this address) |
| 58E0 | 1 | Rev Cut #1 | |
| 58E6 | 1 | Rev Resume #2 | |
| 58EC | 1 | Rev Cut #2 | i think the following 4 points are wrong |
| 595A | 2 | Rev Limit #1 | more info... |
| 5960 | 2 | Rev Limit #2 | |
| 5966 | 2 | Rev Limit #3 | |
| 596C | 2 | Rev Limit #4 | |
| 59A0 | Vtec | auto (?) | |
| 59A2 | Vtec | manual (?) | |
| 5BA7 | Idle | Lookup table for 16-bit target idle RPM as a function of ECT | |
| 6059 | Serial Comm | Lookup table for RAM addresses that can be accessed using 9470 UART mode | |
| 7C9A | Low Fuel (10x20) | more info... | |
| 7D6C | High Fuel (10x15) | ||
| 7E0C | Low Timing (10x20) | ||
| 7ED4 | High Timing (10X15) | ||
| 7C4A | MAP sensor scalers | for fuel | |
| 7C54 | MAP sensor scalers | for ignition | |
| 7C5E | MAP sensor scalers | for lambda table | |
| 7C68 | Rev scalers | low cam fuel/ignition | |
| 7C7C | Rev scalers | high cam fuel/ignition | |
| 7C8B | Rev scalers | lambda table | |
| 7C9A | Fuel map | low cam | |
| 7D6C | Fuel map | high cam | |
| 7E0C | Ignition map | low cam | |
| 7ED4 | Ignition map | high cam | |
| 7F6A | Lambda map | ||
| Attachment: | Modify: | Size: | Date: | Who: | Comment: |
|---|---|---|---|---|---|
 P72OBD1top.jpg | mod | 227251 | 04 Mar 2004 - 00:44 | blundar | Picture of OBD1 P72 (thanks Katman) |
 P72NoKnockGoodchksum.bin | mod | 32768 | 05 Mar 2004 - 18:32 | blundar | P72 ROM with knock disabled + good checksum |
Attachments
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