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 Present

Voltage Readings

E10-2 & E7-24

Always

10-14

E10-13 & E7-24

Ignition On

10-14

E10-12 & E7-24

Ignition On

10-14

E10-1 & E7-24

Ignition On

10-14

E8-1 & E8-9

Ignition On

4-6

E8-11 & E8-9

Ignition On, Throttle Fully Open

10-14

E8-11 & E8-9

Ign. On, Throttle Fully Closed

1 Or Less

E8-10 & E8-9

Ignition On, Throttle Fully Open

2.7-5.2

E8-10 & E8-9

Ign. On, Throttle Fully Closed

0.3-0.8

E8-2 & E8-9

Ignition On

3.7-4.3

E8-2 & E8-9

Engine Idling

2-4

E8-3 & E8-8

Ignition On, Intake Air Temp. 68°F (20°C)

1-3

E8-4 & E8-9

Ignition On, Coolant Temp. 176°F (80°C)

0.1-1

E7-12 & E7-13

Engine Idling

Pulse Gen.

E7-11 & E7-13

Engine Idling

Pulse Gen.

E7-23 & E7-13

Engine Idling

Pulse Gen.

E7-22 & E7-13

Engine Idling

Pulse Gen.

E7-21 & E7-13

Engine Idling

Pulse Gen.

E7-20 & E7-13

Engine Idling

Pulse Gen.

E7-12 & E7-13

Ignition On

10-14

E7-11 & E7-13

Ignition On

10-14

E7-23 & E7-13

Ignition On

10-14

E7-22 & E7-13

Ignition On

10-14

E7-21 & E7-13

Ignition On

10-14

E7-20 & E7-13

Ignition On

10-14

E7-18 & E7-24

Engine Idling

Pulse Gen.

E7-17 & E7-24

Ignition On

1 Or Less

E7-17 & E7-24

Engine Idling

Pulse Gen.

E9-11 & E9-6

Engine Idling

Pulse Gen.

E9-10 & E9-6

Engine Idling

Pulse Gen.

E9-12 & E9-6

Engine Idling

Pulse Gen.

E10-3 & E7-24

Ignition On

10-14

E9-2 & E7-24

Ignition On

10-14

E9-2 & E7-24

High Temperature Restart

2 Or Less

E7-7 & E7-24

Ignition On

10-14

E7-6 & E7-24

Ignition On

10-14

E7-5 & E7-24

Ignition On

10-14

E7-4 & E7-24

Ignition On

10-14

E7-15 & E724

Maintain 2500 RPM 2 Minutes With Engine Warm, Then Idle

1-4

E7-14 & E7-24

Maintain 2500 RPM 2 Minutes With Engine Warm, Then Idle

1-4

E8-5 & E7-24

Maintain 2500 RPM 2 Minutes With Engine Warm

0-1 Pulse

E8-13 & E7-24

Maintain 2500 RPM 2 Minutes With Engine Warm

0-1 Pulse

E7-1 & E7-13

Ignition On

10-14

E7-1 & E7-13

Engine Idling

2 Or Less

E8-6 & E7-24

Engine Idling

Pulse Gen.

E8-14 & E7-24

Engine Idling

Pulse Gen.

E10-22 & E7-24

Ignition On, Gearshift Not In "P" Or "N"

10-14

E10-22 & E7-24

Ignition On Gearshift In "P" Or "N"

2 Or Less

E10-8 & E7-24

Rotate Driving Wheel Ignition On

Pulse Gen.

E8-7 & E7-24

Ignition On

10-14

E8-15 & E7-24

Ignition On

10-14

E10-4 & E7-24

Ignition On

2 Or Less

E10-4 & E7-24

Engine Idling

10-14

E10-18 & E7-24

Ignition On

10-14

E10-7 & E7-24

Engine Idling, A/C On

2 Or Less

E10-7 & E7-24

Engine Idling, A/C Off

10-14

E10-6 & E7-24

Engine Idling, A/C On

10-14

E10-6 & E7-24

Engine Idling, A/C Off

2 Or Less

E9-3 & E7-13

Ignition On

10-14

E10-11 & E7-24

Engine Cranking

6 Or More

E7-25 & E7-13

Engine Starting

10-14

⁽¹⁾	See Fig 1.

ECM VOLTAGE SPECIFICATIONS

Measure Between ECM Terminals ⁽¹⁾

Conditions Present

Voltage Readings

A33 & B69

Always

9-14

A1 & B69

Ignition On

9-14

A31 & B69

Ignition On

9-14

A32 & B69

Ignition On

9-14

B41 & B65

Ignition On

4.5-5.5

B64 & B65

Ignition On, Throttle Fully Open

9-14

B64 & B65

Ign. On, Throttle Fully Closed

0-3

B63 & B65

Ignition On, Throttle Fully Open

9-14

B63 & B65

Ign. On, Throttle Fully Closed

0-3

B43 & B65

Ign. On, Throttle Fully Closed

0.3-0.8

B43 & B65

Ignition On, Throttle Valve Open

3.2-4.9

B42 & B65

Ign. On, Throttle Fully Closed

0.3-0.8

B42 & B65

Ignition On, Throttle Valve Open

3.2-4.9

B66 & B69

Engine Idling

Pulse Gen.

B45 & B65

Engine Idling, Intake Air Temp. 68°F (20°C)

0.5-3.4

B44 & B65

Engine Idling, Coolant Temp. 176°F (80°C)

0.2-1

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.

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

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.

B29 & B69

Maintain 2500 RPM 2 Minutes With Engine Warm, Then Idle

1.8-3.2

B28 & B69

Maintain 2500 RPM 2 Minutes With Engine Warm, Then Idle

1.8-3.2

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 ⁽²⁾

Maintain 2500 RPM 2 Minutes With Engine Warm

Pulse Gen.

B73 & B80 ⁽²⁾

Ignition On

9-14

B72 & B80 ⁽²⁾

Ignition On

9-14

A36 & B80 ⁽²⁾

Ignition On

9-14

B73 & B80 ⁽²⁾

Engine Idling

3 Or Less

B72 & B80 ⁽²⁾

Engine Idling

3 Or Less

A36 & B80 ⁽²⁾

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

Rotate Driving Wheel Ignition On

Pulse Gen.

A20 & B69

Ignition On

9-14

A19 & 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 On

0-1.5

A34 & B69

Engine Idling, A/C Off

7-14

A23 & B69

Engine Idling, A/C On

0-3

A23 & B69

Engine Idling, A/C Off

9-14

A37 & B69

Ignition On

9-14

A40 & B65

Ignition On, Throttle Closed

0.3-0.8

A40 & B65

Ignition On, Throttle Open

3.2-4.9

A39 & B65

Ignition On, Throttle Closed

0.3-0.8

A39 & B65

Ignition On, Throttle Open

3.2-4.9

A38 & B69

Ignition On

4.5-5.5

B36 & B80 ⁽²⁾

Ignition On

9-14

B36 & B80 ⁽²⁾

High Temperature Restart

2 Or Less

A15 & B69

Brake Pedal Depressed, Defogger On

7.5-14

A15 & B69

Defogger On

0-1.5

⁽¹⁾	See Fig 2.

⁽²⁾	GS300 Calif. models.

ECM VOLTAGE SPECIFICATIONS

Measure Between ECM Terminals ⁽¹⁾

Conditions Present

Voltage Readings

E12-14 & E11-16

Always

9-14

E12-9 & E11-16

Ignition On

9-14

E12-22 & E11-16

Ignition On

9-14

E12-23 & E11-16

Ignition On

9-14

E10-1 & E10-22

Ignition On

4.5-5.5

E9-32 & E10-22

Ignition On, Throttle Valve Open

9-14

E9-31 & E10-22

Ign. On, Throttle Valve Closed

0-3

E10-7 & E10-22

Ign. On, Throttle Fully Closed

0.3-0.8

E10-12 & E10-22

Ignition On, Throttle Valve Open

3.2-4.9

E10-8 & E11-16

Engine Idling

Pulse Gen.

E10-18 & E10-22

Engine Idling, Intake Air Temp. 68°F (20°C)

0.5-3.4

E10-20 & E10-22

Engine Idling, Coolant Temp. 176°F (80°C)

0.1-1.0

E9-13 & E11-16

Cranking

6 Or More

E9-10 & E9-34

Engine Idling

Pulse Gen.

E9-9 & E9-34

Engine Idling

Pulse Gen.

E9-8 & E9-34

Engine Idling

Pulse Gen.

E9-7 & E9-34

Engine Idling

Pulse Gen.

E9-24 & E11-16

Engine Idling

Pulse Gen.

E9-25 & E11-16

Engine Idling

Pulse Gen.

E9-12 & E11-16

Ignition On

2 Or Less

E9-2 & E11-16

Engine Idling

Pulse Gen.

E10-10 & E10-11

Engine Idling

Pulse Gen.

E10-16 & E10-11

Engine Idling

Pulse Gen.

E10-5 & E10-6

Engine Idling

Pulse Gen.

E12-13 & E11-16

Ignition On

9-14

E11-4 & E11-16

Ignition On

2 Or Less

E11-4 & E11-16

Engine Idling

5-6 Pulse

E11-1 & E11-16

Engine Idling

7 Or More

E9-15 & E11-16

Ignition On

9-14

E9-15 & E11-16

High Temperature Restart

2 Or Less

E9-26 & E11-16

Engine Idling

9-14

E9-23 & E11-16

Engine Idling

Pulse Gen.

E9-22 & E11-16

Engine Idling

Pulse Gen.

E9-21 & E11-16

Engine Idling

Pulse Gen.

E9-20 & E11-16

Engine Idling

Pulse Gen.

E9-17 & E11-16

Maintain 2500 RPM 2 Minutes With Engine Warm

Pulse Gen.

E9-18 & E11-16

Maintain 2500 RPM 2 Minutes With Engine Warm

Pulse Gen.

E10-13 & E11-16

Maintain 2500 RPM 2 Minutes With Engine Warm

Pulse Gen.

E10-19 & E11-16

Maintain 2500 RPM 2 Minutes With Engine Warm

Pulse Gen.

E10-15 & E9-34

Engine Idling

3 Or Less

E10-14 & E9-34

Ignition On

9-14

E9-30 & E11-16

Ignition On

9-14

E9-29 & E11-16

Ignition On

9-14

E9-28 & E11-16

Ignition On

9-14

E9-27 & E11-16

Ignition On

9-14

E11-7 & E11-16

Engine Idling

Pulse Gen.

E11-11 & E11-16

Engine Idling

Pulse Gen.

E9-14 & E11-16

Ignition On, Gearshift Not In "P" Or "N"

9-14

E9-14 & E11-16

Ignition On, Gearshift In "P" Or "N"

0-3

E12-12 & E11-16

Rotate Driving Wheel Ignition On

Pulse Gen.

E11-5 & E11-16

Ignition On

9-14

E12-11 & E11-16

Ignition On

9-14

E11-3 & E11-16

Ignition On

3 Or Less

E11-3 & E11-16

Engine Idling

9-14

E12-8 & E11-16

Engine Idling

9-14

E12-7 & E11-16

Ignition On

9-14

E12-20 & E11-16

Engine Idling, A/C On

7.5-14

E12-20 & E11-16

A/C Off

2 Or Less

E12-5 & E11-16

Engine Idling, A/C On

3 Or Less

E12-5 & E11-16

A/C Off

9-14

E12-27 & E11-16

Ignition On

9-14

E12-26 & E10-22

Ign. On, Throttle Valve Closed

0.3-0.8

E12-26 & E10-22

Ign. On, Throttle Fully Open

3.2-4.9

E12-25 & E10-22

Ign. On, Throttle Valve Closed

0.3-0.8

E12-25 & E10-22

Ign. On, Throttle Fully Open

3.2-4.9

E12-24 & E11-16

Ignition On

4.5-5.5

E12-10 & E11-16

Air Pump Operating

9-14

E12-10 & E11-16

Air Pump Not Operating

0-3

E11-8 & E11-16

Air Pump Operating

9-14

E11-8 & E11-16

Air Pump Not Operating

0-3

E9-6 & E11-16

Ignition On

9-14

E9-6 & E11-16

Air Pump Operating

0-3

⁽¹⁾	See Fig 3.

ECM VOLTAGE SPECIFICATIONS

Measure Between ECM Terminals ⁽¹⁾

Conditions Present

Voltage Readings

A33 & B69

Always

10-14

A1 & B69

Ignition On

10-14

A31 & B69

Ignition On

10-14

A32 & B69

Ignition On

10-14

B41 & B65

Ignition On

4-6

B64 & B65

Ignition On, Throttle Fully Open

10-14

B64 & B65

Ign. On, Throttle Fully Closed

1 Or Less

B63 & B65

Ignition On, Throttle Fully Open

10-14

B63 & B65

Ign. On, Throttle Fully Closed

1 Or Less

B43 & B65

Ign. On, Throttle Fully Closed

0.1-1

B43 & B65

Ignition On, Throttle Valve Open

3-6

B42 & B65

Ign. On, Throttle Fully Closed

0.1-1

B42 & B65

Ignition On, Throttle Valve Open

3-6

B66 & B69

Engine Idling

Pulse Gen.

B45 & B65

Engine Idling, Intake Air Temp. 68°F (20°C)

1-3

B44 & B65

Engine Idling, Coolant Temp. 176°F (80°C)

0.1-1

B77 & B69

Engine Cranking

6 Or More

B20 & B80

Ignition On

10-14

B18 & B80

Ignition On

10-14

B16 & B80

Ignition On

10-14

B19 & B80

Ignition On

10-14

B17 & B80

Ignition On

10-14

B15 & B80

Ignition On

10-14

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.

B56 & B69

Engine Idling

Pulse Gen.

B58 & B69

Engine Idling

Pulse Gen.

B58 & B69

Ignition On

1 Or Less

B59 & B69

Engine Idling

Pulse Gen.

B59 & B69

Ignition On

2 Or Less

B26 & B6

Engine Idling

Pulse Gen.

B25 & B6

Engine Idling

Pulse Gen.

B27 & B7

Engine Idling

Pulse Gen.

A24 & B69

Ignition On

10-14

A22 & B69

Ignition On

2 Or Less

A22 & B69

Engine Idling

Pulse Gen.

A21 & B69

Engine Idling

7 Or More

B73 & B69

Ignition On

10-14

B73 & B69

High Temperature Restart

2 Or Less

B74 & B69

Engine Idling

10-14

B35 & B69

Ignition On

10-14

B34 & B69

Ignition On

10-14

B33 & B69

Ignition On

10-14

B32 & B69

Ignition On

10-14

B29 & B69

Maintain 2500 RPM 2 Minutes With Engine Warm, Then Idle

1-4

B28 & B69

Maintain 2500 RPM 2 Minutes With Engine Warm, Then Idle

1-4

B48 & B69

Maintain 2500 RPM 2 Minutes With Engine Warm

Pulse Gen.

B47 & B69

Maintain 2500 RPM 2 Minutes With Engine Warm

Pulse Gen.

B71 & B80

Ignition On

10-14

B72 & B80

Ignition On

10-14

B52 & B80

Ignition On

10-14

B53 & B80

Ignition On

10-14

B71 & B80

Engine Idling

2 Or Less

B72 & B80

Engine Idling

2 Or Less

B52 & B80

Engine Idling

2 Or Less

B53 & B80

Engine Idling

2 Or Less

B39 & B69

Ignition On

10-14

B38 & B69

Ignition On

10-14

B37 & B69

Ignition On

10-14

B36 & B69

Ignition On

10-14

B50 & B69

Engine Idling

Pulse Gen.

B49 & B69

Engine Idling

Pulse Gen.

B76 & B69

Ignition On, Gearshift Not In "P" Or "N"

10-14

B76 & B69

Ignition On Gearshift In "P" Or "N"

1 Or Less

A2 & B69

Rotate Driving Wheel Ignition On

Pulse Gen.

A20 & B69

Ignition On

10-14

A19 & B69

Ignition On

10-14

A6 & B69

Ignition On

3 Or Less

A6 & B69

Engine Idling

10-14

A11 & B69

Ignition On

10-14

A12 & B69

Ignition On

4-6

A34 & B69

Engine Idling, A/C On

2 Or Less

A34 & B69

Engine Idling, A/C Off

10-14

A23 & B69

Engine Idling, A/C On

2 Or Less

A23 & B69

Engine Idling, A/C Off

10-14

A37 & B69

Ignition On

10-14

A40 & B65

Ignition On, Throttle Closed

1 Or Less

A40 & B65

Ignition On, Throttle Open

3-5.5

A39 & B65

Ignition On, Throttle Closed

1 Or Less

A39 & B65

Ignition On, Throttle Open

3-5.5

A38 & B69

Ignition On

4-6

⁽¹⁾	See Fig 2.

Fig 1: Identifying ECM Terminals (ES300)

Fig 2: Identifying ECM Terminals (GS300, SC300 & SC400)

Fig 3: Identifying ECM Terminals (LS400)