Engine Controls - Pin Voltage Charts: Introduction

Pin voltage charts are supplied to reduce diagnostic time. Checking pin voltages at the Programmed Fuel Injection Electronic Control Unit (PGM-FI ECU) determines whether it is receiving and transmitting proper voltage signals. Diagnostic charts may also help determine if ECU harness is shorted or open.

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.

CONNECTOR "A" TERMINAL PIN VOLTAGE

TERMINAL ID &(WIRE COLOR)

FUNCTION

VOLTAGE VALUE

A1 (Brown)

Injector No. 1

VBAT ⁽¹⁾

A2 (Wht/Blu)

Injector No. 4

VBAT ⁽¹⁾

A3 (Red)

Injector No. 2

VBAT ⁽¹⁾

A4 (Blk/Red)

Injector No. 5

VBAT ⁽¹⁾

A5 (Orange)

Injector No. 3

VBAT ⁽¹⁾

A6 (Yellow)

Injector No. 6

VBAT ⁽¹⁾

A7 (Grn/Blk)

Fuel Pump Control Circuit

N/A

A8 (Green)

Cooling Fan Control Unit

N/A

A9 (Blu/Red)

Elect Air Control Valve

VBAT ⁽¹⁾

A10 (Grn/Blu)

Left O2 Sensor Heater Circuit

N/A

A11 (White)

EGR Control Solenoid Valve

N/A

A12 (Grn/Red)

Right O2 Sensor Heater Circuit

N/A

A13 (Blue)

Check Engine Light Circuit

N/A

A14 (Red/Blu)

By-Pass Low Control Solenoid Valve

⁽²⁾

A15 (Red/Blu)

A/C Clutch Relay

N/A

A16

Not Used

N/A

A17 (Gray)

Air Suction Control Solenoid Valve

N/A

A18 (Yellow)

By-Pass Hi Control Solenoid Valve

⁽²⁾

A19 (Lt Grn)

Pressure Reg. Control Solenoid Valve

N/A

A20 (Lt Grn)

Purge Cut-Off Solenoid Valve

N/A

A21 (Pink)

No. 1 Coil Ignitor Circuit

N/A

A22 (Brown)

No. 2 Coil Ignitor Circuit

N/A

A23 (Black)

Ground

Less Than 1V

A24 (Black)

Ground

Less Than 1V

A25 (Yel/Blk)

Battery Voltage From Main Relay

VBAT ⁽¹⁾

A26 (Brn/Blk)

Ground

Less Than 1V

⁽¹⁾

Key on, engine off.

⁽²⁾

Battery voltage at idle with key on, engine running.

CONNECTOR "B" TERMINAL PIN VOLTAGE

TERMINAL ID &(WIRE COLOR)

FUNCTION

VOLTAGE VALUE

Not Used

N/A

B2 (Brn/Blk)

Ground

Less Than 1V

B3 (Red)

No. 6 Coil Ignitor Circuit

N/A

B4 (Gray)

No. 5 Coil Ignitor Circuit

N/A

B5 (Green)

P/S Pressure Switch Signal

⁽¹⁾

B6 (Green)

No. 4 Coil Ignitor Circuit

N/A

B7 (White)

M/T Neutral Position Switch

⁽²⁾

B7 (Lt Grn)

A/T Shift Position Switch (P/N)

⁽³⁾

B8 (Blue)

No. 3 Coil Ignitor Circuit

N/A

B9 (Blu/Grn)

Cyl No. 2 Sensor Circuit

N/A

B10 (Blu/Yel)

Cyl No. 2 Sensor Circuit

N/A

B11 (Orn/Blu)

Cyl No. 1 Sensor Circuit

N/A

B12 (Wht/Blu)

Cyl No. 1 Sensor Circuit

N/A

B13 (Orange)

Crank No. 2 Sensor Circuit

N/A

B14 (White)

Crank No. 2 Sensor Circuit in Neutral.

N/A

B15 (Orn/Blu)

Crank No. 1 Sensor Circuit

N/A

B16 (Wht/Blu)

Crank No. 1 Sensor Circuit

N/A

⁽¹⁾

Less than battery voltage with front wheels straight ahead, battery voltage while slowly turning steering wheel (key on, engine running).

⁽²⁾

Less than 1V with key on, engine off and gear selector in Neutral.

⁽³⁾

1V with key on, engine running in Park or Neutral.

CONNECTOR "C" TERMINAL PIN VOLTAGE

TERMINAL ID & (WIRE COLOR)

FUNCTION

VOLTAGE VALUE

C1 (Yel/Blk)

Battery Voltage From Main Relay

⁽¹⁾

C2 (Yel/Red)

Vehicle Speed Sensor

⁽²⁾

C3 (Blu/Blk)

Cooling Fan Control Unit

N/A

C4 (Blue)

Tachometer Signal Output

N/A

C5 (Red/Blu)

A/C Switch Circuit

⁽³⁾

Not Used

N/A

C7 (Pink)

M/T Neutral Switch

⁽⁴⁾

Not Used

N/A

C10

Not Used

N/A

C11 (Blk/Wht)

Start Signal Input

⁽⁵⁾

C12

Not Used

N/A

⁽¹⁾

Battery voltage with key on, engine off.

⁽²⁾

Switches 0V to 5V while turning left front wheel.

⁽³⁾

5V with key on, engine off and A/C off, less than 1V with key on, engine off and A/C on.

⁽⁴⁾

0V with key on, engine off in Neutral, 10V in any gear.

⁽⁵⁾

Battery voltage in START position.

CONNECTOR "D" TERMINAL PIN VOLTAGE

TERMINAL ID & (WIRE COLOR)

FUNCTION

VOLTAGE VALUE

D1 (Yel/Blu)

Voltage From (ACG) Fuse 15

⁽¹⁾

D2 (Grn/Wht)

Brake Switch Signal Input

⁽²⁾

D3 (White)

Right Knock Sensor Circuit

N/A

D4 (Red/Blu)

Left Knock Sensor Circuit

N/A

Not Used

N/A

Not Used

N/A

Not Used

N/A

D8 (Blu/Yel)

Ignition Timing Adjustment Connector

N/A

D9 (Wht/Red)

Alternator Charging Signal

⁽³⁾

D10

Not Used

N/A

D11 (Red/Blu)

Throttle Angle Sensor Signal

⁽⁴⁾

D12 (Blk/Wht)

EGR Valve Lift Sensor Signal

⁽⁵⁾

D13 (Red/Wht)

Intake Air Temp Sensor Signal

0.5-4.5V ⁽⁶⁾

D14 (White)

Left O2 Sensor Signal

⁽⁷⁾

D15 (Red/Yel)

Intake Air Temp Sensor Signal

0.5-4.5V ⁽⁶⁾

D16 (Red/Blu)

Right O2 Sensor Signal

⁽⁷⁾

D17 (Red)

MAP Sensor Signal

0.3-4.5V ⁽⁸⁾

D18

Not Used

N/A

D19 (Yel/Wht)

MAP Sensor Power

5V ⁽⁹⁾

D20 (Yel/Wht)

Sensor Power (Except MAP Sensor)

5V ⁽⁹⁾

D21

MAP Sensor Ground

N/A

D22 (Grn/Yel)

Sensor Ground (Except MAP Sensor)

N/A

⁽¹⁾

Battery voltage at all times.

⁽²⁾

Battery voltage with brake applied (key on, engine off).

⁽³⁾

About 5V with key on, engine off. Decreases under electrical load (Headlights, Defogger on) at warm idle.

⁽⁴⁾

0.3V with key on, engine off at closed throttle, approximately 4.5V at wide open throttle.

⁽⁵⁾

Approximately 1.2V at warm idle.

⁽⁶⁾

Varies with temperature.

⁽⁷⁾

Above 0.6V at WOT at warm 4500 RPM, less than 0.4V when quickly releasing throttle at 4500 RPM.

⁽⁸⁾

Varies with manifold pressure.

⁽⁹⁾

Key on, engine off.

Fig 1: Identifying Connector "A" Terminals

Courtesy of AMERICAN HONDA MOTOR CO., INC.

Fig 2: Identifying Connector "B" Terminals

Courtesy of AMERICAN HONDA MOTOR CO., INC.

Fig 3: Identifying Connector "C" Terminals

Courtesy of AMERICAN HONDA MOTOR CO., INC.

Fig 4: Identifying Connector "D" Terminals

Courtesy of AMERICAN HONDA MOTOR CO., INC.