Control Unit Testing
- Engine must be at normal operating temperature and transmission in Neutral (Park on A/T models). Check the control unit according to Control Unit Testing chart.
- When more than 1 Checking Condition is listed, all conditions must be checked. Connect the negative probe of voltmeter to terminal "P" and positive probe to other terminals as described.
- If a problem exists, check circuit to which terminal is connected. If circuit is normal, replace control unit.
AUXILIARY CONTROL UNIT CHECK CHART
| Terminal | Connection To | Voltage with ignition ON |
|---|---|---|
| A | Ignition coil (-) terminal | approx. 12V |
| B | Ignition switch | approx. 12V |
| C | Choke switch | below 1.5V |
| D | Ignition coil (-) terminal | approx. 12V |
| E | Throttle sensor | approx. 8V |
| F | Switching solenoid valve | approx. 12V |
| G | Throttle sensor | 1 to 2V |
| H | Ignition switch "START" terminal | below 1.5V |
| I | Throttle sensor | 0V |
| J | No. 2 water temperature switch | below 1.5V |
| L | Air-con. solenoid valve | approx. 12V |
| M | Main air bleed solenoid valve | approx. 12V |
| N | Relief solenoid valve | below 2V |
| O | Heat hazard sensor | below 2V |
| P | Ground | 0V |
| Q | Shutter solenoid valve | below 1.5V |
| R | Idle richer solenoid valve | 0V |
| S | Vacuum control solenoid valve (L) | approx. 12V (in neutral) |
| T | Vacuum control solenoid valve (T) | approx. 12V (in neutral) |
| U | Port air solenoid valve | below 1.5V |
| V | Ign. switch "START" terminal | below 1.5V (above 8V at "START") |
| a | Catalyst thermo sensor | below 1.5V |
| b | Not Used | N/A |
| c | Catalyst thermo sensor | below 1.5V |
| h | VSS | 0V: Reed switch (speedometer) - closed 6 to 12V: Reed switch (speedometer) - open |
| i | A/C cut relay | below 1.5V air con. switch OFF |
| j | Not Used | N/A |
| k | Neutral switch | 0V - in gear: approx. 12V - in neutral |
| l | Clutch switch | 0V - pedal released: approx. 12V - depressed |
| m | Not Used | N/A |
| n | Fuel pump cut relay | below 1.5V |