Kohler command pro ECH749 Service Manual page 83

OBD2
P-Code Ap-
Blink
plicable to:
Code
"32 Pin" (MSE
1.1) ECU/Sys-
tem Only
56 P1231
56 P1232
56 P1233
61
NOTE:
1. Idle Switch not used.
2. Diagnostic of TPS-Signal Implausible is disabled in code.
3. O2 Sensor Short to Battery diagnostic detection is disabled with SAS fuel-cutoff calibrated out.
4. Air Temperature Sensor not used.
5. Temperature Sensor Signal Implausible: diagnostic detection is calibrated out, with TPLAUS set to -50°C.
6. System too Lean used to be O2 Sensor-Short to Ground (P0131).
7. System too Rich used to be O2 Sensor Control at Lower Limit (P0019).
8. Obtainable only with ECU 24 584 28-S or later.
9. Will not blink out.
Code 21
Component: Engine Speed Sensor
Fault: ECU receiving inconsistent tooth count
signals from speed sensor.
Condition: Possible misfi re as ECU attempts to
resynchronize, during which time fuel and
spark calculations are not made.
Conclusion: Engine Speed Sensor Related
● Sensor connector or wiring.
● Sensor loose or incorrect air gap.
● Flywheel key sheared
Speed Sensor Ring Gear Related
● Damaged teeth.
● Varying gap (gear loose/out of
alignment).
Engine Wiring Harness Related
"35 Pin" (MA 1.7) Metal-Cased ECU:
● Pin circuits 3 and/or 21 wiring or
connectors.
● Shielding for pin circuits 3 and/or 21
damaged or not properly grounded.
● Poor or improper grounds in system
(battery, ECU, oxygen sensor,
shielding, fuel pump, ignition output).
● Pin circuits 3 and/or 21 routed near
noisy electrical signals (coils, spark
plug lead, plug connector).
24 690 01 Rev. K
Connection or Failure Description
Pump Relay-Open Circuit
Pump Relay-Short Circuit to G
Pump Relay-Short Circuit to B
End of Code Transmission
KohlerEngines.com
EFI SYSTEM-BOSCH
"35 Pin" "24 Pin"
(MA 1.7) (MSE 1.0)
Metal- Plastic-
Cased Cased
ECU/ ECU/Sys-
System tem
N/A N/A
N/A N/A
N/A N/A
Y Y
Engine Wiring Harness Related
"24 Pin" (MSE 1.0) Plastic-Cased ECU:
● Pin circuits 9 and/or 10 wiring or
connectors.
● Shielding for pin circuits 9 and/or 10
damaged or not properly grounded.
● Poor or improper grounds in system
(battery, ECU oxygen sensor, shielding,
fuel pump, ignition output).
● Pin circuits 9 and/or 10 routed near
noisy electrical signals (coils, spark
plug lead, plug connector).
Engine Wiring Harness Related
"32 Pin" (MSE 1.1) Plastic-Cased ECU:
● Pin circuits 9 and/or 10 wiring or
connectors.
● Shielding for pin circuits 9 and/or 10
damaged or not properly grounded.
● Poor or improper grounds in system
(battery, ECU, oxygen sensor,
shielding, fuel pump, ignition output).
● Pin circuits 9 and/or 10 routed near
noisy electrical signals (coils, spark
plug lead, plug connector).
ECU/Harness Related
● ECU-to-harness connection problem.
Ignition System Related
● Non-resistor spark plug(s) used.
"32 Pin"
(MSE
1.1)
Plastic- Note
Cased
ECU/
System
Y
Y
Y
Y
83