Diagnostic procedure

DTC P0121 [BP, BP WITH TC] DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1	VERIFY FREEZE FRAME DATA HAS BEEN RECORDED Has FREEZE FRAME DATA been recorded?	Yes	Go to the next step.
1		No	Record FREEZE FRAME DATA on repair order, then go to the next step.
2	VERIFY RELATED PENDING CODE OR STORED DTC Turn ignition key to ON (Engine off). Retrieve pending code or stored DTC using the WDS or equivalent. Is DTC P0101 also retrieved	Yes	Go to DTC P0101 troubleshooting procedure.
2		No	Go to the next step.
3	VERIFY RELATED REPAIR INFORMATION AVAILABILITY Check for related Service Bulletins and/or online repair information availability. Is any related repair information available?	Yes	Perform repair or diagnostic according to the available repair information. If the vehicle is not repaired, go to the next step.
3		No	Go to the next step.
4	VERIFY CURRENT INPUT SIGNAL STATUS IS CONCERN INTERMITTENT OR CONSTANT Start the engine. Access ECT, TP and MAF PIDs using the WDS or equivalent. Warm up the engine until ECT PID is above 70°C {158°F} Drive the vehicle. Read TP PID when MAF PID is above 63.2 g/s {8.36 lb/min} (BP), 81 g/s {11 lb/min} (BP WITH TC) Is TP PID reading above 12.5% ?	Yes	Go to the next step.
4		No	Intermittent concern exists. Go to INTERMITTENT CONCERNS TROUBLESHOOTING procedure. (See INTERMITTENT CONCERN TROUBLESHOOTING )
5	VERIFY TP PID Clear the DTC from the PCM memory using the WDS or equivalent. Start engine. Access TP, MAF and RPM PIDs using the WDS or equivalent. Read TP PID when MAF PID is below 5.3g/s {0.70 lb/min} and RPM PID is above 500 rpm . Is TP PID reading above 50% ?	Yes	Go to Step 7.
5		No	Go to the next step.
6	VERIFY CURRENT INPUT SIGNAL STATUS IS CONCERN INTERMITTENT OR CONSTANT Drive the vehicle and read MAF PID. Does MAF PID change according to driving condition?	Yes	Intermittent concern exists. Go to INTERMITTENT CONCERN TROUBLESHOOTING procedure. (See INTERMITTENT CONCERN TROUBLESHOOTING .)
6		No	Check MAF sensor and related circuits and terminals. (See MASS AIR FLOW (MAF) SENSOR INSPECTION .) Repair or replace as necessary, then go to Step 11.
7	CHECK TP SENSOR TERMINALS FOR ELECTRICAL CORROSION Turn the ignition switch off. Disconnect TP sensor connector. Check for electrical corrosion on male and female TP sensor terminals. Is any electrical corrosion found?	Yes	Repair or replace suspected terminal or TP sensor, then go to Step 11.
7		No	Go to the next step.
8	CHECK GND CIRCUIT FOR VOLTAGE DROP Check resistance between TP sensor terminal B (harness-side) and body GND. Does resistance read approx.0 ohm ?	Yes	Go to the next step.
8		No	Repair or replace rusted or corroded PCM terminal 4O (harness-side). Disconnect breakout box and go to Step 11.
9	VERIFY TP SENSOR Does TP sensor resistance smoothly change while throttle valve is gradually being opened?	Yes	Go to the next step.
9		No	Replace TP sensor, then go to Step 11.
10	CHECK PCM TERMINALS FOR ELECTRICAL CORROSION Disconnect PCM connector. Check for electrical corrosion on PCM male and female terminals at 4L, 4V and 4O. Is any electrical corrosion found?	Yes	Repair terminal, then go to the next step.
10		No	Go to the next step.
11	VERIFY TROUBLESHOOTING OF DTC P0121 COMPLETED Make sure to connect all disconnected connectors. Start the engine. Clear the DTC from the PCM memory using the WDS or equivalent. Access RPM, ECT, TP and MAF PIDs using the WDS or equivalent. Verify TP PID is reading below 50% while MAF PID is below 5 g/s {0.66 lb/min} and RPM PID is above 500 rpm . Warm up the engine until ECT PID is reading above 70°C {158°F} . Drive the vehicle and read TP and MAF PIDs. Verify PID readings are within specifications MAF PID: above 63.2 g/s {8.36 lb/min} (BP), 81 g/s {11 lb/min} (BP WITH TC) TP PID: above 12.5% more than 5 s Is same DTC present?	Yes	Replace PCM, then go to the next step.
11		No	Go to the next step.
12	VERIFY AFTER REPAIR PROCEDURE Perform the "AFTER REPAIR PROCEDURE ". (See AFTER REPAIR PROCEDURE ) Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE )
12		No	Troubleshooting completed.