Aston Martin diagnostic trouble code
P0603: Powertrain Control Module Keep Alive Memory (KAM) Error
Use this reference to understand the recorded condition, confirm the available V8 Vantage or DB9 manual coverage, and follow the documented diagnostic checks before replacing parts.
- Code family
- Powertrain
- Vehicle system
- Electrical and control modules
- Manual coverage
- V8 Vantage, DB9
- Warning-lamp status
- V8 Vantage: Not stated; DB9: MIL
What Aston Martin code P0603 means
Powertrain Control Module Keep Alive Memory (KAM) Error
DB9 preliminary diagnostic manual · section 2-138
Manufacturer fault-analysis procedure
Manual fault definition
P0603 - The PCM has detected a power interrupt
in the KAM (Keep Alive Memory) supply to the
PCM.
in the KAM (Keep Alive Memory) supply to the
PCM.
Cautions and notes
NOTE: If KAPWR is interrupted to the PCM by disconnecting the battery or any connection in the VBATT
supply circuit to primary PCM pin C0635-45 or secondary PCM pin C0638-45, P0603/P0605 may be generated on the first power up after reconnection or after
re-flashing the PCMs.
CAUTION: This code may be generated in the
Primary or Secondary Powertrain Control Module
(PCM). Check that you are working on the correct
half of the engine.
supply circuit to primary PCM pin C0635-45 or secondary PCM pin C0638-45, P0603/P0605 may be generated on the first power up after reconnection or after
re-flashing the PCMs.
CAUTION: This code may be generated in the
Primary or Secondary Powertrain Control Module
(PCM). Check that you are working on the correct
half of the engine.
Test sequence and decision path
1. Key off. Inspect the battery cables and VBAT supply circuit through the battery disconnect switch
for loose connections, corrosion, etc. Repair as
necessary.
2. Check the security of the keep alive power lines
from the underbonnet fuses F1 and F12 to the
PCMs.
3. Disconnect the PCMs, inspect the connectors for
pushed out pins, damage, corrosion, etc. Repair if
necessary.
4. Fit the PCM break-out box. Measure voltage
between primary PCM harness connector C0635-
45 and chassis ground (KAPWR). Repeat the
check at secondary PCM connector C0638-45.
Whilst measuring the voltage, grasp the PCM harness and wiggle, shake or bend small sections
while working from the PCM to the underbonnet
fusebox.
If the voltage drops below 10.5 volts, service the
open circuit in the KAPWR circuit. Reconnect all
components and rerun the KOER Test to verify
that the problem is resolved.
If the voltage remains above 10.5 volts, rerun the
KOEO self test. If P0603/P0605 is detected again,
consult Aston Martin Technical Support.
If P0603 is not detected, the code was due to
some service action as described in the note following the code description. Testing is then complete.
Open the corresponding manual page for wiring diagrams and figures
for loose connections, corrosion, etc. Repair as
necessary.
2. Check the security of the keep alive power lines
from the underbonnet fuses F1 and F12 to the
PCMs.
3. Disconnect the PCMs, inspect the connectors for
pushed out pins, damage, corrosion, etc. Repair if
necessary.
4. Fit the PCM break-out box. Measure voltage
between primary PCM harness connector C0635-
45 and chassis ground (KAPWR). Repeat the
check at secondary PCM connector C0638-45.
Whilst measuring the voltage, grasp the PCM harness and wiggle, shake or bend small sections
while working from the PCM to the underbonnet
fusebox.
If the voltage drops below 10.5 volts, service the
open circuit in the KAPWR circuit. Reconnect all
components and rerun the KOER Test to verify
that the problem is resolved.
If the voltage remains above 10.5 volts, rerun the
KOEO self test. If P0603/P0605 is detected again,
consult Aston Martin Technical Support.
If P0603 is not detected, the code was due to
some service action as described in the note following the code description. Testing is then complete.