Engine - Low Power, Hesitation, DTCs P0122,P1122,P1390..: Overview

97-074

November 10, 1997

Applies To:
1996-97 Passport - All LX and EX models

Low Power or Intermittent Engine Hesitation; DTC(s) PO122, P1122, P139O, P1391, P1392, and P1406

SYMPTOM
There is low engine power or intermittent engine hesitation, or the check engine light comes on with one or more of the following DTCs:

- P0122 - Low voltage in TP circuit

- P1122 - Intermittent low voltage in TP circuit

- P1390 - Intermittent low voltage in G sensor

- P1391 - Poor G sensor performance

- P1392 - Low voltage from the G sensor

- P1406 - Poor performance from EGR valve pintle position circuit

Also, evaporative emission, oxygen sensor, mass airflow sensor, and automatic transmission related DTCs may set.

PROBABLE CAUSE
If the PGM Tester indicates any of the above DTCs, the condition may be caused by a low resistance ground path in the 5-volt reference line due to a faulty fuel tank pressure sensor.

CORRECTIVE ACTION
Measure the 5-volt reference at the Powertrain Control Module (PCM), and follow the diagnosis procedure to determine if the fuel tank pressure sensor is faulty.

PARTS INFORMATION

Fuel Tank Pressure Sensor:
P/N 8-16257-276-0, H/C 5379540

REQUIRED SPECIAL TOOLS

Backprobe Set:
T/N O7SAZ-001000A, H/C 4615316

WARRANTY CLAIM INFORMATION

In warranty
The normal warranty applies.

Operation number: 121107
Flat rate time: 1.1 hours
Failed part: P/N 8-16217-059-1
H/C 5310842
Defect code: 064
Contention code: C99
Template ID: 97-074A
Skill level: Repair Technician

Out of warranty:
Any repair performed after warranty expiration may be eligible for goodwill consideration by the District Service Manager or your Zone Office. You must request consideration, and get a decision, before starting work.