DTC P1580: Starter Relay Diagnosis Circuit: Notes
1. -
DTC detecting condition:
Detected when two consecutive driving cycles with fault occur.
Trouble symptom:
Auto Start Stop does not operate.
Wiring diagram:
- ENGINE TYPE FB
Auto Start Stop Ref. to WIRING SYSTEM>AUTO START STOP>WIRING DIAGRAM>ENGINE TYPE FB .
Fuse and relay Ref. to WIRING SYSTEM>FUSE AND RELAY>LOCATION>ENGINE COMPARTMENT SIDE (ENGINE TYPE FB) .
- ENGINE TYPE FA
Auto Start Stop Ref. to WIRING SYSTEM>AUTO START STOP>WIRING DIAGRAM>ENGINE TYPE FA .
Fuse and relay Ref. to WIRING SYSTEM>FUSE AND RELAY>LOCATION>PASSENGER ROOM SIDE .
- Use the check board when measuring the ECM terminal voltage and resistance.
- After servicing or replacing faulty parts, perform the last step of the basic diagnostic procedure. Ref. to AUTO START STOP (DIAGNOSTICS)>BASIC DIAGNOSTIC PROCEDURE .
- CHECK DATA MONITOR
.
- Turn the ignition switch to ON.
- Read the data of [Starter relay diagnosis A/D value] in ECM using Subaru Select Monitor. Ref. to ENGINE (DIAGNOSTICS) (H4DO)>DATA MONITOR . Ref. to ENGINE (DIAGNOSTICS) (H4DOTC)>DATA MONITOR .
Is the value of [Starter relay diagnosis A/D value] less than 2 V?
Yes: Go to 2 .
No: Go to 6 .
- CHECK STARTER RELAY
.
- Turn the ignition switch to OFF.
- Remove the starter relay.
- Measure the resistance between starter relay terminals.
Terminals
No. 1 - No. 3:
Is the resistance less than 1 Ω?
Yes: Replace the starter relay. Ref. to STARTING/CHARGING SYSTEMS (H4DO)>STARTER RELAY . Ref. to STARTING/CHARGING SYSTEMS (H4DOTC)>STARTER RELAY .
No: Go to 3 .
- CHECK HARNESS BETWEEN STARTER RELAY AND ECM CONNECTOR
.
- Disconnect the ECM connector.
- Measure the resistance between ECM connector and chassis ground.
Connector and terminal
ENGINE TYPE FB
(B62) No. 2 - Chassis ground:
ENGINE TYPE FA
(B61) No. 9 - Chassis ground:
Is the resistance 1 MΩ or more?
Yes: Go to 4 .
No: Repair the short circuit to ground in harness between starter relay and ECM connector.
- CHECK OUTPUT SIGNAL OF ECM
.
- Install the starter relay.
- Turn the ignition switch to ON.
- Measure the voltage between ECM connector and chassis ground.
Connector and terminal
ENGINE TYPE FB
(B62) No. 2 (+) - Chassis ground (-):
ENGINE TYPE FA
(B61) No. 9 (+) - Chassis ground (-):
Is the voltage 12 V or more?
Yes: Go to 5 .
No: Check for poor contact of ECM connector. Replace the ECM if no fault is found. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>ENGINE CONTROL MODULE (ECM) . Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DOTC)>ENGINE CONTROL MODULE (ECM) .
- CHECK HARNESS BETWEEN STARTER RELAY AND STARTER CUT RELAY AND ECM CONNECTOR
.
- Turn the ignition switch to OFF.
- Measure the resistance between ECM connector and chassis ground.
Connector and terminal
ENGINE TYPE FB
(B62) No. 45 - Chassis ground:
Connector and terminal
ENGINE TYPE FA
(B61) No. 55 - Chassis ground:
Is the resistance 1 MΩ or more?
Yes: Check for poor contact of ECM connector. Replace the ECM if no fault is found. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>ENGINE CONTROL MODULE (ECM) . Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DOTC)>ENGINE CONTROL MODULE (ECM) .
No: Repair the short circuit to ground in harness between starter relay or starter cut relay and ECM connector.
- CHECK DATA MONITOR
.
- Turn the ignition switch to ON.
- Read the data of [Starter relay diagnosis A/D value] in ECM using Subaru Select Monitor. Ref. to ENGINE (DIAGNOSTICS) (H4DO)>DATA MONITOR . Ref. to ENGINE (DIAGNOSTICS) (H4DOTC)>DATA MONITOR .
Is [Starter relay diagnosis A/D value] 10 V or more?
Yes: Go to 7 .
No: Go to 11 .
- CHECK STARTER CUT RELAY
.
- Turn the ignition switch to OFF.
- Remove the starter cut relay.
- Measure the resistance between starter cut relay terminals.
Terminals
No. 1 - No. 3:
Is the resistance less than 1 Ω?
Yes: Replace the starter cut relay. Ref. to STARTING/CHARGING SYSTEMS (H4DO)>STARTER RELAY . Ref. to STARTING/CHARGING SYSTEMS (H4DOTC)>STARTER RELAY .
No: Go to 8 .
- CHECK HARNESS BETWEEN STARTER RELAY AND ECM CONNECTOR
.
- Disconnect the ECM connector.
- Measure the resistance between ECM connector and chassis ground.
Connector and terminal
ENGINE TYPE FB
(B62) No. 24 - Chassis ground:
ENGINE TYPE FA
(B61) No. 8 - Chassis ground:
Is the resistance 1 MΩ or more?
Yes: Go to 9 .
No: Repair the short circuit to ground in harness between starter cut relay and ECM connector.
- CHECK OUTPUT SIGNAL OF ECM
.
- Install the starter cut relay.
- Turn the ignition switch to ON.
- Measure the voltage between ECM connector and chassis ground.
Connector and terminal
ENGINE TYPE FB
(B62) No. 24 (+) - Chassis ground (-):
ENGINE TYPE FA
(B61) No. 8 (+) - Chassis ground (-):
Is the voltage 12 V or more?
Yes: Go to 10 .
No: Check for poor contact of ECM connector. Replace the ECM if no fault is found. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>ENGINE CONTROL MODULE (ECM) . Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DOTC)>ENGINE CONTROL MODULE (ECM) .
- CHECK HARNESS BETWEEN STARTER RELAY AND STARTER CUT RELAY AND ECM CONNECTOR
.
- Turn the ignition switch to ON.
- Measure the voltage between ECM connector and chassis ground.
Connector and terminal
ENGINE TYPE FB
(B62) No. 45 (+) - Chassis ground (-):
ENGINE TYPE FA
(B61) No. 55 (+) - Chassis ground (-):
Is the voltage 12 V or more?
Yes: Repair the short circuit to power supply in harness between starter relay or starter cut relay and ECM connector.
No: Check for poor contact of ECM connector. Replace the ECM if no fault is found. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>ENGINE CONTROL MODULE (ECM) . Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DOTC)>ENGINE CONTROL MODULE (ECM) .
- CHECK DATA MONITOR
.
- Connect the ECM connector.
- Read the data of [Starter relay diagnosis A/D value] in ECM using Subaru Select Monitor. Ref. to ENGINE (DIAGNOSTICS) (H4DO)>DATA MONITOR . Ref. to ENGINE (DIAGNOSTICS) (H4DOTC)>DATA MONITOR .
NOTE:Read the data from Ignition switch ON to Engine being started.
Does the [Starter relay diagnosis A/D value] exceed 10 V?
Yes: The circuit has returned to a normal condition at this time. Reproduce the failure, and then perform the diagnosis again.
NOTE:In this case, temporary poor contact of connector, temporary open or short circuit of harness may be the cause.
No: Go to 12 .
- CHECK HARNESS BETWEEN M/B AND ECM CONNECTOR
.
- Disconnect the connector of ECM connector.
- Measure the resistance of harness between M/B and ECM connector.
Connector and terminal
ENGINE TYPE FB
(M/B) Starter relay No. 4 - (B62) No. 2:
(M/B) Starter cut relay No. 4 - (B62) No. 24:
ENGINE TYPE FA
(M/B) Starter relay No. 4 - (B61) No. 9:
(M/B) Starter cut relay No. 4 - (B61) No. 8:
Is the resistance less than 1 Ω?
Yes: Check for poor contact of ECM connector. Replace the ECM if no fault is found. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>ENGINE CONTROL MODULE (ECM) . Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DOTC)>ENGINE CONTROL MODULE (ECM) .
No: Repair the open circuit of harness and poor contact of coupling connector between M/B and ECM connector.