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 Valve Closed & Vacuum Applied To Throttle Opener | 0-3 | ||||
| B63 & B65 | Ignition On & Sub-Throttle Valve Open | 9-14 | ||||
| B63 & B65 | Ignition On & Sub-Throttle Valve Closed | 0-3 | ||||
| B43 & B65 | Ign. On & Throttle Closed | 0.3-0.8 | ||||
| B43 & B65 | Ign. On & Throttle Fully Open | 3.2-4.9 | ||||
| B42 & B65 | Ign. On & Throttle Closed | 0.3-0.8 | ||||
| B42 & B65 | Ign. On & Throttle Fully Open | 3.2-4.9 | ||||
| B66 & B28 | Engine Idling | 1-2 | ||||
| B45 & B65 | Engine Idling & Intake Air Temperature 68°F (20°C) | 0.5-3.4 | ||||
| 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 | ||||
| B18 & B80 | Ignition On | 9-14 | ||||
| B16 & B80 | Ignition On | 9-14 | ||||
| B19 & B80 | Ignition On | 9-14 | ||||
| B17 & B80 | Ignition On | 9-14 | ||||
| B15 & B80 | Ignition On | 9-14 | ||||
| B20 & B80 | Engine Idling | Pulse Gen. | ||||
| B18 & B80 | Engine Idling | Pulse Gen. | ||||
| B16 & B80 | Engine Idling | Pulse Gen. | ||||
| B19 & B80 | Engine Idling | Pulse Gen. | ||||
| B17 & B80 | Engine Idling | Pulse Gen. | ||||
| B15 & B80 | Engine Idling | Pulse Gen. | ||||
| B57 & B69 | Engine Idling | Pulse Gen. | ||||
| B58 & B69 | Engine Idling | Pulse Gen. | ||||
| B58 & B69 | Ignition On | 2 Or Less | ||||
| B26 & B7 | Engine Idling | Pulse Gen. | ||||
| B25 & B7 | Engine Idling | Pulse Gen. | ||||
| B27 & B7 | Engine Idling | Pulse Gen. | ||||
| B6 & B5 | Engine Idling | Pulse Gen. | ||||
| A24 & B69 | Ignition On | 9-14 | ||||
| A22 & B69 | Ignition On | 0-1.5 | ||||
| A22 & B69 | Engine Idling | Pulse Gen. | ||||
| A21 & B69 | Engine Idling | 7 Or More | ||||
| B39 & B80 | Ignition On | 9-14 | ||||
| B74 & B80 | Ignition On | 9-14 | ||||
| B75 & B80 | Engine Idling | 2 Or Less | ||||
| B75 & B80 | 3500 RPM | 9-14 | ||||
| B35 & B80 | Engine Idling | Pulse Gen. | ||||
| B34 & B80 | Engine Idling | Pulse Gen. | ||||
| B33 & B80 | Engine Idling | Pulse Gen. | ||||
| B32 & B80 | Engine Idling | Pulse Gen. | ||||
| B48 & B69 | Maintain 2500 RPM 2 Minutes With Engine Warm | Pulse Gen. | ||||
| B47 & B69 | Maintain 2500 RPM 2 Minutes With Engine Warm | Pulse Gen. | ||||
| A30 & B69 | Maintain 2500 RPM 2 Minutes With Engine Warm | Pulse Gen. | ||||
| B73 & B80 | Ignition On | 9-14 | ||||
| B72 & B80 | Ignition On | 9-14 | ||||
| A36 & B80 | Ignition On | 9-14 | ||||
| B73 & B80 | Engine Idling | 3 Or Less | ||||
| B72 & B80 | Engine Idling | 3 Or Less | ||||
| A36 & B80 | Engine Idling | 3 Or Less | ||||
| 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 | ||||
| A12 & B69 | Ignition On | 9-14 | ||||
| A34 & B69 | Engine Idling & A/C Off | 0-1.5 | ||||
| A34 & B69 | Engine Idling & A/C On | 7.5-14.0 | ||||
| A23 & B69 | Engine Idling & A/C On | 0-3 | ||||
| A37 & B69 | Ignition On | 9-14 | ||||
| A40 & B65 | Ignition On & Throttle Closed | 0.3-0.8 | ||||
| A40 & B65 | Ignition On & Throttle Fully Open | 3.2-4.9 | ||||
| A39 & B65 | Ignition On & Throttle Closed | 0.3-0.8 | ||||
| A39 & B65 | Ignition On & Throttle Fully Open | 3.2-4.9 | ||||
| A38 & B69 | Ignition On | 4.5-5.5 | ||||
| B36 & B80 | Ignition On | 9-14 | ||||
| B36 & B80 | High Temperature Restart | 2 Or Less | ||||
| A15 & B69 | Defogger On & Taillight Off | 7.5-14.0 | ||||
| A15 & B69 | Defogger Off & Taillight Off | 0-1.5 | ||||
| A8 & B69 | (2) During Transmission | Pulse Gen. | ||||
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