Wont start replaced pcm,icm steering lock assy, the codes are coming up p1120,p1220,p221,p1516. i need help

2006 Pontiac G6 Code P1516 Manf Cntrl Veh Spd Idle Speed

DTC P1350 Bypass Line Monitor
Refer to Ignition Control, Knock Sensors .

Circuit Description
The Ignition Control Module (ICM) sends signals that the PCM requires for fuel control and spark advance calculations. At the start of engine crank, the ICM controls spark advance (Bypass mode.) When the second 3X reference pulse is recognized by the PCM, the PCM applies 5 volts to the Bypass circuit, commanding the ICM to switch spark advance to PCM control (IC mode). An open in the IC circuit or a short to voltage in the Bypass circuit at startup will cause the PCM to monitor IC pulses during crank, when the ICM should be grounding the IC circuit. This condition will set DTC P1350. The engine may be started but will run on Bypass mode timing.

Conditions for Setting the DTC
The PCM monitors IC pulses during crank while Bypass mode spark advance is commanded

Action Taken When the DTC Sets
The PCM will illuminate the malfunction indicator lamp (MIL) during the second consecutive trip in which the diagnostic test has been run and failed.
The PCM will store conditions which were present when the DTC set as Freeze Frame and Failure Records data.
Conditions for Clearing the MIL/DTC
The PCM will turn OFF the MIL during the third consecutive trip in which the diagnostic has been run and passed.
The History DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
The DTC can be cleared by using the scan tool.
Diagnostic Aids
Check for the following conditions:

Poor connection at the PCM. Inspect harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal to wire connection.
Damaged harness. Inspect the wiring harness for damage. If the harness appears to be OK, disconnect the ICM, turn the ignition ON and observe a digital multimeter connected between the IC circuit and B+ while moving connectors and wiring harnesses related to the ICM. A change in voltage will indicate the location of the malfunction.
Reviewing the Fail Records vehicle mileage since the diagnostic test last failed may help determine how often the condition that caused the DTC to be set occurs. This may assist in diagnosing the condition.

Test Description
Number(s) below refer to the step number(s) on the Diagnostic Table.

This vehicle is equipped with a PCM which utilizes an Electrically Erasable Programmable Read Only Memory (EEPROM). When the PCM is being replaced, the new PCM must be programmed.

Yes i have worked on these vehicles but never come across this before ,check the glow plugs and the relay to check their all working which i suspect that either the relay/timer is faulty or all 4 glow plugs are gone ,failing which you may need to return the vehicle to the dealer to have the computer re-flashed but i suspect a faulty timer relay or on a 2003 vehicle all four glow plugs are burnt out ,not difficult to change though as their on the top of the engine

I replaced the resister to the blower and now it works

First off when you say it won't start does the motor turn over but won't start or does it do nothing

Hi Robert, It would help us to know which vehicle as the codes very well may be vehicle specific.Ford seem to have codes of that numerical range, so I'm assuming your vehicle is made by Ford.
P1120 refers to the Air flow sensor. P1120 the throttle position sensor. 1220 Series Throttle Control Fault (probably related to the TPS) 1221 Refers to the high speed fuel pump relay having been activated. 1516 Intake manifold runner input error. Cannot find P1514 Hope this is helpful. I suggest sorting out the air flow sensor and the throttle position sensor to begin with and that may sort out the other defects. Very often one sensor giving an error reading will trigger others. Regards John

1. This engine uses the Throttle Actuator Control (TAC) system. Thoroughly clean the throttle bore and throttle plate.

2. Inspect the air intake system for a missing or contaminated air filter

there is also a tsb on it TSB 07-06-04-003 for p1516 that involves replacing the pcm

Subject:LSJ, L61, LK5, L52, LL8 Engine -- Reduced Engine Power, MIL/SES Light, DTC P1516, P2135, P2138 (Replace PCM)

Models:2005-2006 Chevrolet Cobalt, Cobalt SS, Malibu
2006 Chevrolet Colorado, TrailBlazer
2006 GMC Canyon, Envoy
2006 HUMMER H3
2005-2006 Saturn ION, ION Red Line
2006 Saab 9-7X
with ECOTECTM 2.0L, 2.2L I-4 Cylinder Engine (VINs P, F-- RPOs LSJ, L61) or
VORTECTM 2.8L I-4, 3.5L I-5, 4.2L I-6 Cylinder Engine (VINs 8, 6, S -- RPOs LK5, L52, LL8)



Attention: The following bulletin information is only to be used if the customer has returned for REPEAT repairs for DTCs P1516, P2135 and/or P2138.



Condition

Some customers may comment on engine operation in the Reduce Engine Power mode with the MIL/SES light illuminated. This condition may be repeated and upon investigation, the technician may find the following DTCs set as current or in history:

• DTC P1516 Throttle Actuator Control (TAC) Module Throttle Actuator Position Performance
• DTC P2135 Throttle Position (TP) Sensor 1-2 Correlation
• DTC P2138 Accelerator Pedal Position (APP) Sensor 1-2 Correlation
Cause

This condition of a repeat DTC P1516, P2135 and/or P2138 may be caused by an internal concern with the PCM.
Correction



Attachments are only available to registered users.

Register Here


Attachments are only available to registered users.

Register Here

Important: DO NOT replace the APP sensor. Inspect the PCM build date first.

Before following the diagnostic information in SI on DTCs P1516, P2135 and/or P2138, an inspection of the PCM serial number year and Julian (PCM build) date will be necessary to determine if the PCM will need to be replaced to correct the repeat DTC P1516. Refer to Engine Control Module Replacement in SI in order to remove the PCM. Refer to the above graphic illustration (1) for the location of the PCM serial number.

The serial number is read left to right. The last digit of the year is the 9th character and the Julian date is comprised of the 10th, 11th and 12th characters and is used to determine the PCM build date. Refer to the example below to read a build date from the PCM serial number:

* 8 6 Y N AU K 1 5 3 2 5 0 R P N *

If the PCM year and Julian dates are between 5182 and 5304 , replace the PCM. Refer to the Part Catalog to order the correct PCM for your vehicle application, if necessary.

Vehicles with PCM built outside the dates should refer to SI diagnostics for DTCs P1516, P2135 and/or P2138

DTC P1744 means that the PCM has detected excessive slip in the TC. Refer to the section in the WSM (WorkShop Manual) that is applicable for your transmission for diagnosis.

Usually it means that the TC hasn't been getting enough hydraulic pressure in the TC apply circuit to lock it and it slips. When it slips, the clutch surface in the TC is usually ruined. You'll need to have the hydraulic concern repaired first, then replace the TC.

DTC P1120 - CHECK FOR FRAYED TP CIRCUIT WIRES OR CORROSION ON CONNECTORS
Frayed wires.
Corrosion on TP sensor, PCM or harness connectors.
VREF harness opens or shorts.
Damaged TP sensor.
Damaged PCM.

Diagnostic Trouble Code (DTC) P1120 indicates the TP signal is within the Self-Test range but below the closed throttle position range of 3.43% to 9.80% (0.17 to 0.49 volt).

Note: Throttle Position Sensor A (TP-A) is the same as Throttle Position (TP) Sensor.

Possible causes:
Perform a complete visual inspection of the harness connector at the TP sensor (including pins) for corrosion.
Perform a complete visual inspection of the harness wires between the TP sensor and the PCM for insulation fraying and corrosion.

Hope this helps; also keep in mind that your feedback is important and I`ll appreciate your time and consideration if you leave some testimonial comment about this answer.

Thank you for using FixYa, have a nice day.

Your CODE P1276 refer to the Acelerator Pedal Position, Sensor 1 Circuit Range Performance.

Probable cause: Wiring, APP or ECM


GM - P1271 Accelerator Pedal Position Sensor 1-2 Correlation

I also found this... though its for Trailblazers... but may give you a clue:
Reduced Engine Power Message and/or Check Engine Light with any Combination of the following DTCs: P0107 P0112 P0122 P0452 P1120 P1220 P1221 P1271 P1275 P1280 P1481 P1515 P1540 P1633 P1635 P1639 P1682 #PIP3192 - (Oct 18, 2004)

Reduced Engine Power Message and/or Check Engine Light with any Combination of the Following DTCs: P0107 P0112 P0122 P0452 P1120 P1220 P1221 P1271 P1275 P1280 P1481 P1515 P1540 P1633 P1635 P1639 P1682 PCM Repeat.

The following diagnosis might be helpful if the vehicle exhibits the symptom described in the PI.

Condition/Concern:
Reduced engine power message and/or check engine light with any combination of the following DTCs: P0107 P0112 P0122 P0452 P1120 P1220 P1221 P1271 P1275 P1280 P1481 P1515 P1540 P1633 P1635 P1639 P1682

Recommendation/Instructions:
If the SI diagnostics did not isolate a concern, the following information may be helpful:
- Inspect the main engine wiring harness between the PCM and the generator assembly for a potential short to ground. There is a metal wiring harness retainer in this area that secures the main engine harness. If the harness conduit is mispositioned, some of the wiring may become exposed and chaff on the harness retainer. This may eventually cause the exposed circuit to short to ground.

- Inspect the 3 harnesses that connect to the PCM for potential shorts to ground on the metal PCM mounting bracket, just below the PCM. There are plastic harness retainers on the PCM bracket that secure the harnesses to the PCM bracket. If the harness conduit is mispositioned, some of the wiring may become exposed and chaff on the PCM bracket. This may eventually cause the exposed circuit to short to ground.

- If a chaffed circuit is found in either of the above locations, repair the circuit using the necessary SI procedures. Once the circuit is repaired, tape the area of the affected area of the harness to prevent the wires from becoming exposed in the future and secure the harness using the original harness retainer.

This applies to 04:
- 4.2L 5.3L LL8 LM4 Engine with DTC - P2120 or P2122 or P2123 or P2125 or P2127 or P2128 - kw low MIL pedal power reduced #PI01746 - (Feb 17, 2004)
- 4.2L 5.3L LL8 LM4 Engine with DTC - P2120 or P2122 or P2123 or P2125 or P2127 or P2128.

When servicing the vehicle with the VIN you entered, the following diagnosis might be helpful if the vehicle exhibits the described symptoms.

Condition/Concern:
MIL light on. Reduced Power message on DIC. Possibles DTCs P2120 and/or P2122, P2123, P2127, and P2128.

Recommendation/Instructions:
The APP harness is clipped to the accelerator pedal bracket. The harness may chaff on the upper portion of the accelerator pedal causing a short to ground. Verify the harness is not chaffing on the accelerator pedal. After repairing the short, reposition the harness to ensure no contact between the harness and the accelerator pedal.

Hope helpes.