Service manual

G420F(FE) Service Manual Chapter 9. Advanced Diagnostics 298
Table 2. Diagnostic Fault Codes (Flash Codes) cont’d.
DFC PROBABLE FAULT FAULT ACTION *
CORRECTIVE ACTION
FIRST CHECK
491
(29)
HbridgeFault_ETC
Electronic Throttle Control
Driver has failed.
Indeterminate fault on
Hbridge driver for electronic
throttle control. Possibly
either ETC+ or ETC- driver
signals have been shorted to
ground
TurnOnMil
Check ETC driver wiring for a shorted
circuit
SECM Pin A17 to ETC + Pin 1
SECM Pin A18 to ETC - Pin 4
Check the ETC internal motor drive by
disconnecting the throttle connector
and measuring the motor drive
resistance at the throttle
TPS Pin 1 (+DRIVER) to
Pin 4 (-DRIVER) ~3.0-4.0
521
(52)
LowOilPressureFault
Low engine oil pressure
(1) TurnOnMil
(2) DelayedEngine
Shutdown
(3) CheckEngine Light
Check engine oil level
Check electrical connection to the oil
pressure switch
SECM Pin B9 to Oil Pressure Switch
531
(53)
SysVoltRangeLow
System voltage too low
TurnOnMil
Check battery voltage
• Perform maintenance check on
electrical connections to the battery
and chassis ground
• Check battery voltage during starting
and with the engine running to verify
charging system and alternator
function
• Measure battery power at SECM with
a multimeter (with key on) SECM Pin
A23 (DRVP) to
SECM Pin A16 (DRVG)
SECM Pin A23 (DRVP) to
SECM Pin B17 (DRVG)
541
(54)
SysVoltRangeHigh
System voltage too high
TurnOnMil
Check battery and charging system
voltage
•Check battery voltage during starting
and with the engine running
•Check voltage regulator, alternator,
and charging system
•Check battery and wiring for
overheating and damage
• Measure battery power at SECM with
a multimeter (with key on) SECM Pin
A23 (DRVP) to
SECM Pin A16 (DRVG)
SECM Pin A23 (DRVP) to
SECM Pin B17 (DRVG)
(*) Fault actions shown are default values specified by the OEM.