Pinpoint Test AF: DTC P1606; EMS CONTROL RELAY MALFUNCTION

NOTE: Before commencing this test, check the date codes on the relay. If the date is between R6 k1 and R6 k8, change the relay.

CHECK THE EMS RELAY PERMANENT B+ SUPPLY
Remove the EMS relay.

Measure the voltage between the relay base, pins 02 and 03 and GROUND.

Are both voltages greater than 10 volts?

YES: Go to step 3.

NO: REPAIR the circuit between the relay base and battery. This circuit includes the high power protection module. For additional information, refer to the wiring diagrams. CLEAR the DTC. TEST the system for normal operation.
CHECK THE EMS RELAY TO ECM CIRCUIT FOR HIGH RESISTANCE
Disconnect the battery negative terminal.

Disconnect the ECM electrical connector, EM80.

Measure the resistance between the relay base, pin 05 and EM80, pins 23 (WR) and 24 (WR).

Is either resistance greater than 5 ohms?

YES: REPAIR the high resistance circuit. For additional information, refer to the wiring diagrams. CLEAR the DTC. TEST the system for normal operation.

NO: Go to step 3.
CHECK THE ECM TO EMS RELAY CONTROL CIRCUIT FOR HIGH RESISTANCE
Disconnect the battery negative terminal.

Disconnect the ECM electrical connector, EM80.

Measure the resistance between the relay base, pin 01 and EM80, pin 40 (U).

Is the resistance greater than 5 ohms?

YES: REPAIR the high resistance circuit. For additional information, refer to the wiring diagrams. CLEAR the DTC. TEST the system for normal operation.

NO: INSTALL a new EMS relay. CLEAR the DTC. TEST the system for normal operation.