P1657

D : DTC P1251, P1658, P1631, P1657

D1 : CHECK THE THROTTLE MOTOR RELAY

1. Turn the ignition switch to the RUN position.

Does the throttle relay make an audible click?
Yes
Goto D2

No
Goto D8

D2 : CHECK THE PCM POWER SUPPLY FROM THE THROTTLE MOTOR RELAY

1. Measure the voltage between the throttle motor relay connector JB34-138 and ground.

Is the voltage greater than 10 volts?
Yes
Goto D3

No
Goto D4

D3 : CHECK CONTINUITY OF THE PCM POWER SUPPLY WIRE FROM THE THROTTLE MOTOR RELAY

1. Turn the ignition switch to the OFF position.
2. Disconnect the PCM electrical connector EN16 and remove the throttle motor relay.
3. Measure the resistance between the throttle motor relay electrical connector JB34-138 and the PCM electrical connector EN16-134.

Is the resistance less than 5 ohms?
Yes
DIAGNOSE the electronic engine control system.

No
REPAIR the PCM power supply wire from the throttle motor relay. CLEAR the DTC. TEST the system for normal operation.

D4 : CHECK FUSE 33 IN THE ENGINE COMPARTMENT FUSE BOX.

1. Check the fuse.

Is the fuse OK?
Yes
Goto D5

No
Goto D6

D5 : CHECK THE THROTTLE MOTOR RELAY POWER SUPPLY CIRCUIT

1. Remove the throttle motor relay.
2. Measure the voltage between the throttle motor relay connector JB34-139 and ground.

Is the voltage less than 10 volts?
Yes
REPAIR the throttle motor relay power supply circuit. CLEAR the DTC. TEST the system for normal operation.

No
INSTALL a new throttle motor relay. CLEAR the DTC. TEST the system for normal operation.

D6 : CHECK FUSE 33 FOR A SHORT TO GROUND

1. Measure the resistance between fuse 33 and ground.

Is the resistance greater than 10,000 ohms?
Yes
INSTALL a new fuse. CLEAR the DTC. TEST the system for normal operation.

No
REPAIR short to ground between engine compartment fuse box and the throttle motor relay. INSTALL a new fuse. CLEAR the DTC. TEST the system for normal operation.

D7 : CHECK FUSE 36 IN THE ENGINE COMPARTMENT FUSE BOX

1. Check the fuse.

Is the fuse OK?
Yes
Goto D7

No
Goto D10

D8 : CHECK THE POWER SUPPLY CIRCUIT TO THE THROTTLE MOTOR RELAY COIL

1. Turn the ignition switch to the RUN position.
2. Measure the voltage between the throttle motor relay connector JB34-137 and ground.

Is the voltage greater than 10 volts?
Yes
Goto D11

No
Goto D9

D9 : CHECK CONTINUITY OF THE POWER SUPPLY CIRCUIT TO THE THROTTLE MOTOR RELAY COIL

1. Disconnect the PCM electrical connector EN16 and remove the throttle motor relay.
2. Measure the resistance between the throttle motor relay electrical connector JB34-137 and the PCM electrical connector EN16-52.

Is the resistance less than 5 ohms?
Yes
Goto D11

No
REPAIR the throttle motor relay coil power supply circuit from the engine compartment fuse box. CLEAR the DTC. TEST the system for normal operation.

D10 : CHECK FUSE 36 OF THE PASSENGER COMPARTMENT FUSE BOX FOR A SHORT TO GROUND

1. Measure the resistance between fuse 36 of the passenger compartment fuse box and ground.

Is the resistance less than 10,000 ohms?
Yes
REPAIR short to ground between the engine compartment fuse box and the throttle motor relay coil. CLEAR the DTC. TEST the system for normal operation.

No
INSTALL a new fuse. CLEAR the DTC. TEST the system for normal operation.

D11 : CHECK CONTINUITY OF THE THROTTLE MOTOR RELAY COIL

1. Remove the throttle motor relay (if not already removed).
2. Measure the resistance between terminal 1 and terminal 2 of the throttle motor relay.

Is the resistance between 70 and 90 ohms?
Yes
Goto D12

No
INSTALL a new throttle motor relay. CLEAR the DTC. TEST the system for normal operation.

D12 : CHECK CONTINUITY OF THE THROTTLE MOTOR RELAY GROUND CIRCUIT

1. Disconnect the PCM electrical connector EN16.
2. Measure the resistance between the throttle motor relay electrical connector JB34-135 and the PCM electrical connector EN16-52.

Is the resistance less than 5 ohms?
Yes
DIAGNOSE the electronic engine control system.

No
REPAIR the throttle motor relay ground circuit from the PCM to the engine compartment fuse box. CLEAR the DTC. TEST the system for normal operation.