Ecu Input Signals

Timing control and triggering of the fuel injectors are based on input signals from the TDC/CRANK/CYL sensors. These sensors are simple Permanent Magnet (PM) generator pick-up coils.
Using a DVOM (preferably with bar-graph function) on low-volt scale, check each sensor for pulse voltage signal at indicated ECU harness terminals with engine cranking. See ECU INPUT SIGNAL & RESISTANCE TEST TERMINALS table. If pulse signal is present, sensor is okay. If pulse signal is not present, go to next step.

Ensure ignition is off. Check wiring connections. Check resistance of each sensor at indicated ECU harness terminals. See ECU INPUT SIGNAL & RESISTANCE TEST TERMINALS table. If resistance is not within specification, go to step 5). If resistance is within specification, go to next step.

ECU INPUT SIGNAL & RESISTANCE TEST TERMINALS

Application

ECU Terminals ⁽¹⁾

Resistance

Integra

CRANK

B10 & B12

350-700 Ohms

CYL

C1 & C2

350-700 Ohms

TDC

C3 & C4

350-700 Ohms

Legend

CRANK No. 1

B15 & B16

600-950 Ohms

CRANK No. 2

B14 & B13

600-950 Ohms

CYL No. 1

B12 & B11

600-950 Ohms

CYL No. 2

B9 & B10

600-950 Ohms

⁽¹⁾	Terminal identifications are imprinted on ECU connector.

Check continuity to ground on each terminal. If continuity exists, disconnect sensor connector, and recheck appropriate ECU terminal for continuity to ground. If continuity still exists, repair short to ground in harness. If continuity does not exist, replace sensor assembly.
Disconnect sensor connector at sensor. See Fig 1 and Fig 2 . Check resistance of sensor. See ECU INPUT SIGNAL & RESISTANCE TEST TERMINALS tables. If resistance is within specification, repair open, short or corrosion in sensor harness between ECU and sensor. If sensor resistance is not within specification, replace sensor assembly.

Fig 1: Identifying Sensor Connector Terminals (Integra)
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Fig 2: Identifying Sensor Connector Terminals (Legend)
Courtesy of AMERICAN HONDA MOTOR CO., INC.