Pinpoint Test B: One-Touch Integrated Start (OTIS) Does Not Operate Correctly
Starting System
Refer to Wiring Diagram Set 20 for schematic and connector information Diagrams By Number.
Pinpoint Tests
Pinpoint Test B: One-Touch Integrated Start (OTIS) Does Not Operate Correctly
Refer to Wiring Diagram Set 20, Starting System for schematic and connector information Diagrams By Number.
Normal Operation
Under normal operation, the Battery Junction Box (BJB) supplies constant power to the starter motor relay through fuse 13 (30A). When the key is placed in the START position, power is sent to the start diode through circuit CDC35 (BU/WH). Power continues through circuit CE336 (GN/WH) to the PCM and to the starter relay (TorqShift transmission) or the digital Transmission Range (TR) sensor (4R75 transmission). If the TR is in either the PARK or NEUTRAL position, power flows to the starter relay through circuit CET40 (GN/OG).
On vehicles equipped with a TorqShift transmission, the PCM will receive a signal from the transmission that the vehicle is in PARK or NEUTRAL through circuit VET32 (VT).
The PCM then provides ground on circuit CDC12 (YE) to the starter motor relay. The coil of the relay is energized and sends power to the starter motor on circuit CDC25 (BN/GN). The solenoid is grounded at the starter motor. Energizing the starter solenoid will engage the starter drive into the flexplate ring gear and closes the solenoid contacts allowing power directly from the battery through circuit SDC02 (RD) to the starter motor to start the engine.
The PCM will disengage the starter motor based on rpm threshold, a set time has been exceeded or the ignition key has been turned to the OFF position.
This pinpoint test is intended to diagnose the following:
- Circuitry
- PCM
PINPOINT TEST B: OTIS DOES NOT OPERATE CORRECTLY
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B1 CHECK THE STATUS OF OTIS (OTS_STAT) PID
- Enter the following diagnostic mode on the scan tool: PCM DataLogger/PID.
- Monitor the PCM PID OTS_STAT with the ignition switch in the RUN position.
- Is the OTIS PID enabled?
Yes
GO to B2.
No
ENABLE One-Touch Integrated Start (OTIS). TEST the system for normal operation. If OTIS will not enable, INSTALL a new PCM. REFER to Computers and Control Systems. TEST the system for normal operation.
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B2 CHECK THE KEY POSITION FOR START INDICATED (START_KEY) PID
- Enter the following diagnostic mode on the scan tool: PCM DataLogger/PID.
- Monitor the PCM PID START_KEY with the ignition switch in the START position.
- Does the PID change from OFF to ON?
Yes
GO to B4.
No
GO to B3.
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B3 CHECK CIRCUIT CDC35 (BU/WH) FOR AN OPEN
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
- Disconnect: Start Diode.
- Disconnect: PCM C175B (4.6L or 5.4L engines) or PCM C1551B (6.8L engines).
- For vehicles equipped with a 4.6L or 5.4L engine, measure the resistance between start diode cavity 2, circuit CDC35 (BU/WH) and PCM C175B-16, circuit CDC35 (BU/WH), harness side.
- For vehicles equipped with a 6.8L engine, measure the resistance between start diode cavity 2 circuit CDC35 (BU/WH) and PCM C1551B-20, circuit CDC35 (BU/WH).
- Is the resistance less than 5 ohms?
Yes
DIAGNOSE the PCM. REFER to Computers and Control Systems Information.
No
REPAIR circuit CDC35 (BU/WH). TEST the system for normal operation.
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B4 CHECK THE STARTER MOTOR RELAY ENABLE (STRT_RLY) PID
- Enter the following diagnostic mode on the scan tool: PCM DataLogger/PID.
- Monitor the PCM PID STRT_RLY with the ignition switch in the START position.
- Does the PID change from DISABLED to ENABLED?
Yes
GO to B6.
No
GO to B5.
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B5 CHECK THE STARTER MOTOR CONTROL OUTPUT DETECTED (SMC_MON) PID
- Enter the following diagnostic mode on the scan tool: PCM DataLogger/PID.
- Monitor the PCM PID SMC_MON with the ignition switch in the START position.
- Does the PID change from OFF to ON?
Yes
GO to B6.
No
DIAGNOSE the PCM. REFER to Computers and Control Systems Information.
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B6 CHECK CIRCUIT CE336 (GN/WH) BETWEEN THE START DIODE AND THE PCM FOR AN OPEN
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
- Disconnect: Start Diode.
- Disconnect: PCM C175B (4.6L or 5.4L engines) or PCM C1551B (6.8L engines).
- For vehicles equipped with a 4.6L or 5.4L engine, measure the resistance between start diode cavity 1, circuit CE336 (GN/WH) and PCM C175B-37, circuit CE336 (GN/WH), harness side.
- For vehicles equipped with a 6.8L engine, measure the resistance between start diode cavity 1 circuit CE336 (GN/WH) and PCM C1551B-38, circuit CE336 (GN/WH).
- Is the resistance less than 5 ohms?
Yes
DIAGNOSE the PCM. REFER to Computers and Control Systems Information.
No
REPAIR circuit CE336 (GN/WH). TEST the system for normal operation.
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