DTC P1250: Early Fuel EVAP (EFE) Heater CKT Malfunction

Check for blown EFE fuse (30-amp) in engine compartment relay/fuse box. If fuse is okay, go to next step. If fuse is blown, check for short in EFE circuit. Repair as necessary. Retest system.
Ensure engine is cool. Start engine. Using a voltmeter, measure voltage (backprobe) between ground and PCM harness connector "B", terminal No. 12. With engine coolant temperature less than 176°F (80°C) and engine speed greater than 800 RPM, reading should be greater than one volt. As engine warms up, reading should drop to less than one volt. If reading is not as specified, go to next step. If reading is as specified, check for an intermittent problem. See TESTS W/O CODES article.

Turn ignition off. Remove EFE heater relay located in engine compartment relay/fuse box. See Figure . Using an ohmmeter, measure resistance between specified terminals. Refer to the EFE HEATER RELAY RESISTANCE table. If resistance is as specified, go to next step. If resistance is not as specified, replace EFE heater relay.

EFE HEATER RELAY RESISTANCE

Between Terminals No.

Ohms

1 & 2

Infinity

1 & 2

⁽¹⁾ Continuity

3 & 4

19-95

⁽¹⁾	With battery voltage applied to terminals No. 3 and 4.

Disconnect PCM harness connectors. Using an ohmmeter, measure resistance between ground and PCM harness connector "C", terminal No. 12. If resistance is 0.5-30 ohms at 68°F (20°C), go to next step. If resistance is not as specified, check White/Blue wire between PCM and EFE heater for an open or short. Repair as necessary. If wire is okay, replace EFE heater. Retest system.
Check White wire between EFE heater fuse and EFE heater relay for an open or short. Check Yellow/Red wire or White/Blue wire between PCM and EFE heater relay for an open or short. Repair as necessary. If wires are okay, replace PCM. Retest system.