Engine Controls - Pin Voltage Charts: Introduction
Pin voltage charts are supplied to reduce diagnostic time. Checking pin voltages at the Electronic Control Module (ECM) determines whether it is receiving and transmitting proper voltage signals. Charts may also help determine if ECM harness is shorted or opened.
NOTE:
Unless stated otherwise in testing procedures, perform all voltage tests using a Digital Volt-Ohmmeter (DVOM) with a minimum 10-megohm input impedance. Voltage readings may vary slightly due to battery condition or charging rate.
ECM VOLTAGE SPECIFICATIONS
| Measure Between ECM Terminals (1) | Conditions | Volts | ||
|---|---|---|---|---|
| A33 & B69 | Always | 9-14 | ||
| A1 & B69 | Ignition On | 9-14 | ||
| A31 & B69 | Ignition On | 9-14 | ||
| B41 & B65 | Ignition On | 4.5-5.5 | ||
| B64 & B65 | Ignition On & Main Throttle Valve Open | 9-14 | ||
| B64 & B65 | Ignition On & Main Throttle Valve Closed | 3 Or Less | ||
| B63 & B65 | Ignition On & Sub-Throttle Valve Open | 9-14 | ||
| 63 & B65 | Ignition On & Sub-Throttle Valve Closed | 3 Or Less | ||
| B43 & B65 | Ignition On & Main Throttle Valve Closed | .3-.8 | ||
| B43 & B65 | Ignition On & Main Throttle Valve Open | 3.2-4.9 | ||
| B42 & B65 | Ignition On & Sub-Throttle Valve Closed | .3-.8 | ||
| B42 & B65 | Ignition On & Sub-Throttle Valve Open | 3.2-4.9 | ||
| B66 & B70 | Engine Idling | 1.1-1.5 | ||
| B45 & B65 | Engine Idling & Intake Air Temperature 68°F (20°C) | .5-3.4 | ||
| B44 & B65 | Engine Idling & Coolant Temperature 176°F (80°C) | 0.2-1.0 | ||
| B77 & B69 | Engine Cranking | 6 Or More | ||
| B20 & B80 | Ignition On | 9-14 | ||
| B19 & B80 | Ignition On | 9-14 | ||
| B18 & B80 | Ignition On | 9-14 | ||
| B17 & B80 | Ignition On | 9-14 | ||
| B16 & B80 | Ignition On | 9-14 | ||
| B15 & B80 | Ignition On | 9-14 | ||
| B40 & B80 | Ignition On | 9-14 | ||
| B39 & B80 | Ignition On | 9-14 | ||
| B20 & B80 | Engine Idling | Pulse Gen. | ||
| B19 & B80 | Engine Idling | Pulse Gen. | ||
| B18 & B80 | Engine Idling | Pulse Gen. | ||
| B17 & B80 | Engine Idling | Pulse Gen. | ||
| B16 & B80 | Engine Idling | Pulse Gen. | ||
| B15 & B80 | Engine Idling | Pulse Gen. | ||
| B40 & B80 | Engine Idling | Pulse Gen. | ||
| B39 & B80 | Engine Idling | Pulse Gen. | ||
| B57 & B69 | Engine Idling | Pulse Gen. | ||
| B56 & B69 | Engine Idling | Pulse Gen. | ||
| B58 & B69 | Engine Idling | Pulse Gen. | ||
| B58 & B69 | Ignition On | 2 Or Less | ||
| B59 & B69 | Engine Idling | Pulse Gen. | ||
| B59 & B69 | Ignition On | 2 Or Less | ||
| B26 & B6 | Engine Idling | Pulse Gen. | ||
| B25 & B5 | Engine Idling | Pulse Gen. | ||
| B27 & B7 | Engine Idling | Pulse Gen. | ||
| A24 & B69 | Ignition On | 9-14 | ||
| A22 & B69 | Ignition On | 2 Or Less | ||
| A22 & B69 | Engine Idling | Pulse Gen. | ||
| A21 & B69 | Engine Idling | 7 Or More | ||
| B71 & B69 | Ignition On | 9-14 | ||
| B71 & B69 | High Temperature Restart | 2 Or Less | ||
| B51 & B69 | Engine Idling | 9-14 | ||
| A29 & B69 | Ignition On | 9-14 | ||
| A30 & B65 | Ignition On | 2.9-3.7 | ||
| A30 & B65 | Ignition On & 1.2 in. Hg (4 kPa) Applied To Vapor Pressure Sensor | 0-0.5 | ||
| B24 & B65 | Oil Temp. At 176°F (80°C) | .2-1.0 | ||
| B35 & B69 | Ignition On | 9-14 | ||
| B34 & B69 | Ignition On | 9-14 | ||
| B33 & B69 | Ignition On | 9-14 | ||
| B32 & B69 | Ignition On | 9-14 | ||
| B47 & B69 | Maintain 2500 RPM 2 Minutes With Engine Warm | Pulse Gen. | ||
| B48 & B69 | Maintain 2500 RPM 2 Minutes With Engine Warm | Pulse Gen. | ||
| B73 & B80 | Ignition On | 9-14 | ||
| B72 & B80 | Ignition On | 9-14 | ||
| B75 & B80 | Ignition On | 9-14 | ||
| B74 & B80 | Ignition On | 9-14 | ||
| B73 & B80 | Engine Idling | 3 Or Less | ||
| B72 & B80 | Engine Idling | 3 Or Less | ||
| B75 & B80 | Engine Idling | 3 Or Less | ||
| B74 & B80 | Engine Idling | 3 Or Less | ||
| B55 & B69 | Ignition On | 9-14 | ||
| B54 & B69 | Ignition On | 9-14 | ||
| B53 & B69 | Ignition On | 9-14 | ||
| B52 & B69 | Ignition On | 9-14 | ||
| B46 & B65 | Ignition On | 4.5-5.5 | ||
| B50 & B69 | Engine Idling | Pulse Gen. | ||
| B49 & B69 | Engine Idling | Pulse Gen. | ||
| B76 & B69 | Ignition On & Gearshift Not In "P" Or "N" | 9-14 | ||
| B76 & B69 | Ignition On & Gearshift In "P" Or "N" | 3 Or Less | ||
| A2 & B69 | Ignition On & Rotate Driving Wheel | Pulse Gen. | ||
| A20 & B69 | Ignition On | 9-14 | ||
| A6 & B69 | Ignition On | 3 Or Less | ||
| A6 & B69 | Engine Idling | 9-14 | ||
| A11 & B69 | Engine Idling | 9-14 | ||
| A12 & B69 | Ignition On | 9-14 | ||
| A34 & B69 | Engine Idling & A/C On | 2 Or Less | ||
| A34 & B69 | Engine Idling & A/C Off | 9-14 | ||
| A23 & B69 | Engine Idling & A/C On | 2 Or Less | ||
| A23 & B69 | Engine Idling & A/C Off | 9-14 | ||
| A40 & B65 | Ignition On & Throttle Closed | .3-.8 | ||
| A40 & B65 | Ignition On & Throttle Fully Open | 3.2-4.9 | ||
| A39 & B65 | Ignition On & Throttle Closed | .3-.8 | ||
| A39 & B65 | Ignition On & Fully Throttle Open | 3.2-4.9 | ||
| A38 & B69 | Ignition On | 4.5-5.5 | ||
| A4 & B69 | Ignition On & Brake Pedal Pressed | 7.5-14.0 | ||
| A4 & B69 | Ignition On & Brake Pedal Released | 0-1.5 | ||
|
||||