KJ: Supercharge Bypass Control

KJ: Introduction See: KJ: Supercharger Bypass Control - Introduction

KJ1 DTC P0234: CHECK FOR OTHER DTCS

Note: The supercharger will be bypassed when the brake is on and the throttle is depressed in the wide open throttle position. This is called brake torque and the engine torque is too high.

• Check that the engine has not been subjected to brake torque causing the P0234.
• Drive the vehicle for 10 to 15 minutes with the engine exceeding 2,000 rpm and the engine temperature stabilizing.
• No Starts:
• GO to A1 See: Diagnostic Trouble Code Tests and Associated Procedures\SECTION 5: Pinpoint Tests\A: No Start - Pinpoint Test.
• For Stalls:
• Return to Section 3 , Symptom Charts. See: Symptom Related Diagnostic Procedures
• Return to repair area and check that upper radiator hose is hot and pressurized.
• Rerun Quick Test and retrieve KOER and continuous and retrieve DTCs.

Are any other KOEO, KOER and Continuous Memory DTCs present with the KOER or Continuous Memory P0234?
Yes

• KEY OFF. GO to Section 4, Powertrain Diagnostic Trouble Code (DTC) Charts See: A L L Diagnostic Trouble Codes ( DTC )\Testing and Inspection\Diagnostic Trouble Code Descriptions

, for Pinpoint Test direction
and REPAIR DTCs.

No

• GO to KJ2

.

KJ2 CHECK SCAN TOOL PIDS FOR CAUSES OF OVERBOOST CONDITION

• Key on, engine running.
• Access IAT2, TFT and RPM PIDs.
• Observe the PIDs for values exceeding the following limits:
• Intake air temperature (downstream), IAT2 PID greater than 230°F.
• Transmission fluid temperature, TFT PID greater than 275°F.

Do any of the above PIDs exceed the limit?
Yes

• For IAT2:
• CHECK for low fluid level in Intercooler System. CHECK for cracked intercooler

lines. REPAIR as necessary.

• For TFT:
• CHECK for low transmission fluid level. REFER to Automatic Transmission/Transaxle for fluid changes.

No

• GO to KJ3

.

KJ3 CHECK FOR LOW SPEED FUEL PUMP RELAY NOT SWITCHING

• Key on, engine running.
• Access LFPF PID.

Is a fault indicated on the low speed fuel pump (FP) output?
Yes

• KEY OFF. GO to Section 4, Powertrain Diagnostic Trouble Code (DTC) Charts See: A L L Diagnostic Trouble Codes ( DTC )\Testing and Inspection\Diagnostic Trouble Code Descriptions

for diagnostic direction
following DTC P1232.

No

• CHECK for indications of engine knock while driving the vehicle.

REPAIR as necessary. If OK, indicate to vehicle owner that transmission damage
will occur upon brake torque (reference: GO to KJ1
). Otherwise,
unable to determine cause of overboost condition at this time.

KJ6 DTC P0243: CHECK SUPERCHARGER (BOOST) BYPASS SOLENOID OUTPUT

• Key off.
• Disconnect supercharger (boost) bypass (SCB) solenoid.
• Connect a non-powered test lamp between SCB and VPWR circuits at the SCB solenoid harness connector.
• Key on, engine off.
• Attempt to close and open SCB solenoid driver in PCM by accessing Output Test Mode or scan tool.
• While observing the test lamp, command the PCM outputs on and off.

Does the test lamp cycle on and off (light up and turn off)?
Yes

• KEY OFF. GO to KJ7

.

No

• For test lamp always off

:

• GO to KJ8

.

• For test lamp always on

:

• KEY OFF. GO to KJ11

.

KJ7 CHECK SCB SOLENOID RESISTANCE

• Measure SCB solenoid resistance.

Is resistance between 68 and 78 ohms?
Yes

• CHECK for damaged vacuum hoses between engine intake manifold

and SCB solenoid. CHECK for vacuum reservoir assembly leaks. REPAIR or REPLACE
as necessary. If OK, GO to Z1 See: Diagnostic Trouble Code Tests and Associated Procedures\SECTION 5: Pinpoint Tests\Z: Intermittent - Pinpoint Test
for intermittent diagnosis.

No

• REPLACE damaged SCB solenoid.

KJ8 CHECK FOR OPEN VPWR CIRCUIT BETWEEN SCB SOLENOID AND POWER RELAY

• Measure voltage between VPWR circuit at the SCB solenoid harness connector and battery negative post.

Is voltage greater than 10.5 volts?
Yes

• KEY OFF. GO to KJ9

.

No

• KEY OFF. REPAIR open circuit.

KJ9 CHECK VPWR CIRCUIT FOR OPEN IN HARNESS

Note: Refer to the PCM connector pin numbers in the beginning of the pinpoint test.

• Disconnect PCM.
• Measure resistance of VPWR circuit between PCM harness connector pin and SCB solenoid harness connector.

Is resistance less than 5.0 ohms?
Yes

• GO to KJ10

.

No

• REPAIR open circuit.

KJ10 CHECK SCB CIRCUIT FOR OPEN IN HARNESS

• Measure resistance of SCB circuit between PCM harness connector pin and SCB solenoid harness connector.

Is resistance less than 5.0 ohms?
Yes

• REPLACE PCM (refer to Section 2, Flash Electrically Erasable Programmable Read Only Memory (EEPROM) See: Programming and Relearning\Flash Electrically Eraseable Programmable Read Only Memory - Flash EEPROM).

No

• REPAIR open circuit.

KJ11 CHECK SCB CIRCUIT FOR SHORT TO PWR GND IN HARNESS

Note: Refer to the PCM connector pin numbers in the beginning of this pinpoint test.

• Disconnect PCM.
• Disconnect scan tool from DLC.
• Measure resistance between SCB circuit and multiple PWR GND circuits at the PCM harness connector.

Are all resistances greater than 10,000 ohms?
Yes

• RECONNECT scan tool. GO to KJ12

.

No

• REPAIR short circuit.

KJ12 CHECK SCB CIRCUIT FOR SHORT TO PWR IN HARNESS

• Key on, engine off.
• Measure voltage between SCB circuit at the PCM harness connector and chassis ground.

Is voltage less than 1.0 volts?
Yes

• KEY OFF. REPLACE PCM (refer to Section 2, Flash Electrically Erasable Programmable Read Only Memory (EEPROM) See: Programming and Relearning\Flash Electrically Eraseable Programmable Read Only Memory - Flash EEPROM

).

No

• KEY OFF. REPAIR short circuit to VPWR.

KJ13 LACK OF POWER (LOW BOOST)- CHECK VACUUM HOSES

• Check for holes or cracks in the vacuum hose/tube between the supercharger bypass actuator and the supercharger bypass solenoid.
• Check for holes or cracks in the vacuum hose/tube between the supercharger bypass solenoid and vacuum reservoir assembly.
• Check for bends or kinks in the vacuum hose/tube between the supercharger bypass actuator and the supercharger bypass solenoid.
• Check for bends or kinks in the vacuum hose/tube between the supercharger bypass solenoid and vacuum reservoir assembly.
• Check for disconnect hose(s) between the supercharger bypass actuator, supercharger bypass solenoid and vacuum reservoir assembly.

Are any leaks (holes or cracks) or restrictions (bends or kinks) in the vacuum hose(s) present?
Yes

• REPAIR or REPLACE vacuum hose(s)/tube as necessary.

No

• RETURN to Section 3, Symptom Chart 8 for Lack/Loss of Power. See: Symptom Related Diagnostic Procedures